Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

19 files changed, 10996 insertions, 0 deletions

diff --git a/vendor/flume/tests/after.rs b/vendor/flume/tests/after.rs
new file mode 100644
index 0000000..6d25108
--- /dev/null
+++ b/vendor/flume/tests/after.rs
@@ -0,0 +1,339 @@
+// //! Tests for the after channel flavor.
+
+// #[macro_use]
+// extern crate crossbeam_channel;
+// extern crate crossbeam_utils;
+// extern crate rand;
+
+// use std::sync::atomic::AtomicUsize;
+// use std::sync::atomic::Ordering;
+// use std::thread;
+// use std::time::{Duration, Instant};
+
+// use crossbeam_channel::{after, Select, TryRecvError};
+// use crossbeam_utils::thread::scope;
+
+// fn ms(ms: u64) -> Duration {
+//     Duration::from_millis(ms)
+// }
+
+// #[test]
+// fn fire() {
+//     let start = Instant::now();
+//     let r = after(ms(50));
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+//     thread::sleep(ms(100));
+
+//     let fired = r.try_recv().unwrap();
+//     assert!(start < fired);
+//     assert!(fired - start >= ms(50));
+
+//     let now = Instant::now();
+//     assert!(fired < now);
+//     assert!(now - fired >= ms(50));
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+
+//     select! {
+//         recv(r) -> _ => panic!(),
+//         default => {}
+//     }
+
+//     select! {
+//         recv(r) -> _ => panic!(),
+//         recv(after(ms(200))) -> _ => {}
+//     }
+// }
+
+// #[test]
+// fn capacity() {
+//     const COUNT: usize = 10;
+
+//     for i in 0..COUNT {
+//         let r = after(ms(i as u64));
+//         assert_eq!(r.capacity(), Some(1));
+//     }
+// }
+
+// #[test]
+// fn len_empty_full() {
+//     let r = after(ms(50));
+
+//     assert_eq!(r.len(), 0);
+//     assert_eq!(r.is_empty(), true);
+//     assert_eq!(r.is_full(), false);
+
+//     thread::sleep(ms(100));
+
+//     assert_eq!(r.len(), 1);
+//     assert_eq!(r.is_empty(), false);
+//     assert_eq!(r.is_full(), true);
+
+//     r.try_recv().unwrap();
+
+//     assert_eq!(r.len(), 0);
+//     assert_eq!(r.is_empty(), true);
+//     assert_eq!(r.is_full(), false);
+// }
+
+// #[test]
+// fn try_recv() {
+//     let r = after(ms(200));
+//     assert!(r.try_recv().is_err());
+
+//     thread::sleep(ms(100));
+//     assert!(r.try_recv().is_err());
+
+//     thread::sleep(ms(200));
+//     assert!(r.try_recv().is_ok());
+//     assert!(r.try_recv().is_err());
+
+//     thread::sleep(ms(200));
+//     assert!(r.try_recv().is_err());
+// }
+
+// #[test]
+// fn recv() {
+//     let start = Instant::now();
+//     let r = after(ms(50));
+
+//     let fired = r.recv().unwrap();
+//     assert!(start < fired);
+//     assert!(fired - start >= ms(50));
+
+//     let now = Instant::now();
+//     assert!(fired < now);
+//     assert!(now - fired < fired - start);
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn recv_timeout() {
+//     let start = Instant::now();
+//     let r = after(ms(200));
+
+//     assert!(r.recv_timeout(ms(100)).is_err());
+//     let now = Instant::now();
+//     assert!(now - start >= ms(100));
+//     assert!(now - start <= ms(150));
+
+//     let fired = r.recv_timeout(ms(200)).unwrap();
+//     assert!(fired - start >= ms(200));
+//     assert!(fired - start <= ms(250));
+
+//     assert!(r.recv_timeout(ms(200)).is_err());
+//     let now = Instant::now();
+//     assert!(now - start >= ms(400));
+//     assert!(now - start <= ms(450));
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn recv_two() {
+//     let r1 = after(ms(50));
+//     let r2 = after(ms(50));
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             select! {
+//                 recv(r1) -> _ => {}
+//                 recv(r2) -> _ => {}
+//             }
+//         });
+//         scope.spawn(|_| {
+//             select! {
+//                 recv(r1) -> _ => {}
+//                 recv(r2) -> _ => {}
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn recv_race() {
+//     select! {
+//         recv(after(ms(50))) -> _ => {}
+//         recv(after(ms(100))) -> _ => panic!(),
+//     }
+
+//     select! {
+//         recv(after(ms(100))) -> _ => panic!(),
+//         recv(after(ms(50))) -> _ => {}
+//     }
+// }
+
+// #[test]
+// fn stress_default() {
+//     const COUNT: usize = 10;
+
+//     for _ in 0..COUNT {
+//         select! {
+//             recv(after(ms(0))) -> _ => {}
+//             default => panic!(),
+//         }
+//     }
+
+//     for _ in 0..COUNT {
+//         select! {
+//             recv(after(ms(100))) -> _ => panic!(),
+//             default => {}
+//         }
+//     }
+// }
+
+// #[test]
+// fn select() {
+//     const THREADS: usize = 4;
+//     const COUNT: usize = 1000;
+//     const TIMEOUT_MS: u64 = 100;
+
+//     let v = (0..COUNT)
+//         .map(|i| after(ms(i as u64 / TIMEOUT_MS / 2)))
+//         .collect::<Vec<_>>();
+//     let hits = AtomicUsize::new(0);
+
+//     scope(|scope| {
+//         for _ in 0..THREADS {
+//             scope.spawn(|_| {
+//                 let v: Vec<&_> = v.iter().collect();
+
+//                 loop {
+//                     let timeout = after(ms(TIMEOUT_MS));
+//                     let mut sel = Select::new();
+//                     for r in &v {
+//                         sel.recv(r);
+//                     }
+//                     let oper_timeout = sel.recv(&timeout);
+
+//                     let oper = sel.select();
+//                     match oper.index() {
+//                         i if i == oper_timeout => {
+//                             oper.recv(&timeout).unwrap();
+//                             break;
+//                         }
+//                         i => {
+//                             oper.recv(&v[i]).unwrap();
+//                             hits.fetch_add(1, Ordering::SeqCst);
+//                         }
+//                     }
+//                 }
+//             });
+//         }
+//     })
+//     .unwrap();
+
+//     assert_eq!(hits.load(Ordering::SeqCst), COUNT);
+// }
+
+// #[test]
+// fn ready() {
+//     const THREADS: usize = 4;
+//     const COUNT: usize = 1000;
+//     const TIMEOUT_MS: u64 = 100;
+
+//     let v = (0..COUNT)
+//         .map(|i| after(ms(i as u64 / TIMEOUT_MS / 2)))
+//         .collect::<Vec<_>>();
+//     let hits = AtomicUsize::new(0);
+
+//     scope(|scope| {
+//         for _ in 0..THREADS {
+//             scope.spawn(|_| {
+//                 let v: Vec<&_> = v.iter().collect();
+
+//                 loop {
+//                     let timeout = after(ms(TIMEOUT_MS));
+//                     let mut sel = Select::new();
+//                     for r in &v {
+//                         sel.recv(r);
+//                     }
+//                     let oper_timeout = sel.recv(&timeout);
+
+//                     loop {
+//                         let i = sel.ready();
+//                         if i == oper_timeout {
+//                             timeout.try_recv().unwrap();
+//                             return;
+//                         } else if v[i].try_recv().is_ok() {
+//                             hits.fetch_add(1, Ordering::SeqCst);
+//                             break;
+//                         }
+//                     }
+//                 }
+//             });
+//         }
+//     })
+//     .unwrap();
+
+//     assert_eq!(hits.load(Ordering::SeqCst), COUNT);
+// }
+
+// #[test]
+// fn stress_clone() {
+//     const RUNS: usize = 1000;
+//     const THREADS: usize = 10;
+//     const COUNT: usize = 50;
+
+//     for i in 0..RUNS {
+//         let r = after(ms(i as u64));
+
+//         scope(|scope| {
+//             for _ in 0..THREADS {
+//                 scope.spawn(|_| {
+//                     let r = r.clone();
+//                     let _ = r.try_recv();
+
+//                     for _ in 0..COUNT {
+//                         drop(r.clone());
+//                         thread::yield_now();
+//                     }
+//                 });
+//             }
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn fairness() {
+//     const COUNT: usize = 1000;
+
+//     for &dur in &[0, 1] {
+//         let mut hits = [0usize; 2];
+
+//         for _ in 0..COUNT {
+//             select! {
+//                 recv(after(ms(dur))) -> _ => hits[0] += 1,
+//                 recv(after(ms(dur))) -> _ => hits[1] += 1,
+//             }
+//         }
+
+//         assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+//     }
+// }
+
+// #[test]
+// fn fairness_duplicates() {
+//     const COUNT: usize = 1000;
+
+//     for &dur in &[0, 1] {
+//         let mut hits = [0usize; 5];
+
+//         for _ in 0..COUNT {
+//             let r = after(ms(dur));
+//             select! {
+//                 recv(r) -> _ => hits[0] += 1,
+//                 recv(r) -> _ => hits[1] += 1,
+//                 recv(r) -> _ => hits[2] += 1,
+//                 recv(r) -> _ => hits[3] += 1,
+//                 recv(r) -> _ => hits[4] += 1,
+//             }
+//         }
+
+//         assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+//     }
+// }
diff --git a/vendor/flume/tests/array.rs b/vendor/flume/tests/array.rs
new file mode 100644
index 0000000..a72bbe3
--- /dev/null
+++ b/vendor/flume/tests/array.rs
@@ -0,0 +1,657 @@
+//! Tests for the array channel flavor.
+
+extern crate crossbeam_utils;
+extern crate rand;
+
+use std::any::Any;
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
+use std::thread;
+use std::time::Duration;
+
+use flume::{bounded, Receiver};
+use flume::{RecvError, RecvTimeoutError, TryRecvError};
+use flume::{SendError, SendTimeoutError, TrySendError};
+use crossbeam_utils::thread::scope;
+use rand::{thread_rng, Rng};
+
+fn ms(ms: u64) -> Duration {
+    Duration::from_millis(ms)
+}
+
+#[test]
+fn smoke() {
+    let (s, r) = bounded(1);
+    s.send(7).unwrap();
+    assert_eq!(r.try_recv(), Ok(7));
+
+    s.send(8).unwrap();
+    assert_eq!(r.recv(), Ok(8));
+
+    assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+    assert_eq!(r.recv_timeout(ms(1000)), Err(RecvTimeoutError::Timeout));
+}
+
+#[test]
+fn capacity() {
+    for i in 1..10 {
+        let (s, r) = bounded::<()>(i);
+        assert_eq!(s.capacity(), Some(i));
+        assert_eq!(r.capacity(), Some(i));
+    }
+}
+
+#[test]
+fn len_empty_full() {
+    let (s, r) = bounded(2);
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(s.is_empty(), true);
+    assert_eq!(s.is_full(), false);
+    assert_eq!(r.len(), 0);
+    assert_eq!(r.is_empty(), true);
+    assert_eq!(r.is_full(), false);
+
+    s.send(()).unwrap();
+
+    assert_eq!(s.len(), 1);
+    assert_eq!(s.is_empty(), false);
+    assert_eq!(s.is_full(), false);
+    assert_eq!(r.len(), 1);
+    assert_eq!(r.is_empty(), false);
+    assert_eq!(r.is_full(), false);
+
+    s.send(()).unwrap();
+
+    assert_eq!(s.len(), 2);
+    assert_eq!(s.is_empty(), false);
+    assert_eq!(s.is_full(), true);
+    assert_eq!(r.len(), 2);
+    assert_eq!(r.is_empty(), false);
+    assert_eq!(r.is_full(), true);
+
+    r.recv().unwrap();
+
+    assert_eq!(s.len(), 1);
+    assert_eq!(s.is_empty(), false);
+    assert_eq!(s.is_full(), false);
+    assert_eq!(r.len(), 1);
+    assert_eq!(r.is_empty(), false);
+    assert_eq!(r.is_full(), false);
+}
+
+#[test]
+fn try_recv() {
+    let (s, r) = bounded(100);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+            thread::sleep(ms(1500));
+            assert_eq!(r.try_recv(), Ok(7));
+            thread::sleep(ms(500));
+            assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected));
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            s.send(7).unwrap();
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn recv() {
+    let (s, r) = bounded(100);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(r.recv(), Ok(7));
+            thread::sleep(ms(1000));
+            assert_eq!(r.recv(), Ok(8));
+            thread::sleep(ms(1000));
+            assert_eq!(r.recv(), Ok(9));
+            assert!(r.recv().is_err());
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1500));
+            s.send(7).unwrap();
+            s.send(8).unwrap();
+            s.send(9).unwrap();
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn recv_timeout() {
+    let (s, r) = bounded::<i32>(100);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(r.recv_timeout(ms(1000)), Err(RecvTimeoutError::Timeout));
+            assert_eq!(r.recv_timeout(ms(1000)), Ok(7));
+            assert_eq!(
+                r.recv_timeout(ms(1000)),
+                Err(RecvTimeoutError::Disconnected)
+            );
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1500));
+            s.send(7).unwrap();
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn try_send() {
+    let (s, r) = bounded(1);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(s.try_send(1), Ok(()));
+            assert_eq!(s.try_send(2), Err(TrySendError::Full(2)));
+            thread::sleep(ms(1500));
+            assert_eq!(s.try_send(3), Ok(()));
+            thread::sleep(ms(500));
+            assert_eq!(s.try_send(4), Err(TrySendError::Disconnected(4)));
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            assert_eq!(r.try_recv(), Ok(1));
+            assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+            assert_eq!(r.recv(), Ok(3));
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn send() {
+    let (s, r) = bounded(1);
+
+    scope(|scope| {
+        scope.spawn(|_| {
+            s.send(7).unwrap();
+            thread::sleep(ms(1000));
+            s.send(8).unwrap();
+            thread::sleep(ms(1000));
+            s.send(9).unwrap();
+            thread::sleep(ms(1000));
+            s.send(10).unwrap();
+        });
+        scope.spawn(|_| {
+            thread::sleep(ms(1500));
+            assert_eq!(r.recv(), Ok(7));
+            assert_eq!(r.recv(), Ok(8));
+            assert_eq!(r.recv(), Ok(9));
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn send_timeout() {
+    let (s, r) = bounded(2);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(s.send_timeout(1, ms(1000)), Ok(()));
+            assert_eq!(s.send_timeout(2, ms(1000)), Ok(()));
+            assert_eq!(
+                s.send_timeout(3, ms(500)),
+                Err(SendTimeoutError::Timeout(3))
+            );
+            thread::sleep(ms(1000));
+            assert_eq!(s.send_timeout(4, ms(1000)), Ok(()));
+            thread::sleep(ms(1000));
+            assert_eq!(s.send(5), Err(SendError(5)));
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            assert_eq!(r.recv(), Ok(1));
+            thread::sleep(ms(1000));
+            assert_eq!(r.recv(), Ok(2));
+            assert_eq!(r.recv(), Ok(4));
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn send_after_disconnect() {
+    let (s, r) = bounded(100);
+
+    s.send(1).unwrap();
+    s.send(2).unwrap();
+    s.send(3).unwrap();
+
+    drop(r);
+
+    assert_eq!(s.send(4), Err(SendError(4)));
+    assert_eq!(s.try_send(5), Err(TrySendError::Disconnected(5)));
+    assert_eq!(
+        s.send_timeout(6, ms(500)),
+        Err(SendTimeoutError::Disconnected(6))
+    );
+}
+
+#[test]
+fn recv_after_disconnect() {
+    let (s, r) = bounded(100);
+
+    s.send(1).unwrap();
+    s.send(2).unwrap();
+    s.send(3).unwrap();
+
+    drop(s);
+
+    assert_eq!(r.recv(), Ok(1));
+    assert_eq!(r.recv(), Ok(2));
+    assert_eq!(r.recv(), Ok(3));
+    assert!(r.recv().is_err());
+}
+
+#[test]
+fn len() {
+    const COUNT: usize = 25_000;
+    const CAP: usize = 1000;
+
+    let (s, r) = bounded(CAP);
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(r.len(), 0);
+
+    for _ in 0..CAP / 10 {
+        for i in 0..50 {
+            s.send(i).unwrap();
+            assert_eq!(s.len(), i + 1);
+        }
+
+        for i in 0..50 {
+            r.recv().unwrap();
+            assert_eq!(r.len(), 50 - i - 1);
+        }
+    }
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(r.len(), 0);
+
+    for i in 0..CAP {
+        s.send(i).unwrap();
+        assert_eq!(s.len(), i + 1);
+    }
+
+    for _ in 0..CAP {
+        r.recv().unwrap();
+    }
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(r.len(), 0);
+
+    scope(|scope| {
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                assert_eq!(r.recv(), Ok(i));
+                let len = r.len();
+                assert!(len <= CAP);
+            }
+        });
+
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                s.send(i).unwrap();
+                let len = s.len();
+                assert!(len <= CAP);
+            }
+        });
+    })
+    .unwrap();
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(r.len(), 0);
+}
+
+#[test]
+fn disconnect_wakes_sender() {
+    let (s, r) = bounded(1);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(s.send(()), Ok(()));
+            assert_eq!(s.send(()), Err(SendError(())));
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            drop(r);
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn disconnect_wakes_receiver() {
+    let (s, r) = bounded::<()>(1);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert!(r.recv().is_err());
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            drop(s);
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn spsc() {
+    const COUNT: usize = 100_000;
+
+    let (s, r) = bounded(3);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            for i in 0..COUNT {
+                assert_eq!(r.recv(), Ok(i));
+            }
+            assert!(r.recv().is_err());
+        });
+        scope.spawn(move |_| {
+            for i in 0..COUNT {
+                s.send(i).unwrap();
+            }
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn mpmc() {
+    const COUNT: usize = 25_000;
+    const THREADS: usize = 4;
+
+    let (s, r) = bounded::<usize>(3);
+    let v = (0..COUNT).map(|_| AtomicUsize::new(0)).collect::<Vec<_>>();
+
+    scope(|scope| {
+        for _ in 0..THREADS {
+            scope.spawn(|_| {
+                for _ in 0..COUNT {
+                    let n = r.recv().unwrap();
+                    v[n].fetch_add(1, Ordering::SeqCst);
+                }
+            });
+        }
+        for _ in 0..THREADS {
+            scope.spawn(|_| {
+                for i in 0..COUNT {
+                    s.send(i).unwrap();
+                }
+            });
+        }
+    })
+    .unwrap();
+
+    for c in v {
+        assert_eq!(c.load(Ordering::SeqCst), THREADS);
+    }
+}
+
+#[test]
+fn stress_oneshot() {
+    const COUNT: usize = 10_000;
+
+    for _ in 0..COUNT {
+        let (s, r) = bounded(1);
+
+        scope(|scope| {
+            scope.spawn(|_| r.recv().unwrap());
+            scope.spawn(|_| s.send(0).unwrap());
+        })
+        .unwrap();
+    }
+}
+
+#[test]
+fn stress_iter() {
+    const COUNT: usize = 100_000;
+
+    let (request_s, request_r) = bounded(1);
+    let (response_s, response_r) = bounded(1);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            let mut count = 0;
+            loop {
+                for x in response_r.try_iter() {
+                    count += x;
+                    if count == COUNT {
+                        return;
+                    }
+                }
+                request_s.send(()).unwrap();
+            }
+        });
+
+        for _ in request_r.iter() {
+            if response_s.send(1).is_err() {
+                break;
+            }
+        }
+    })
+    .unwrap();
+}
+
+#[test]
+fn stress_timeout_two_threads() {
+    const COUNT: usize = 100;
+
+    let (s, r) = bounded(2);
+
+    scope(|scope| {
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                if i % 2 == 0 {
+                    thread::sleep(ms(50));
+                }
+                loop {
+                    if let Ok(()) = s.send_timeout(i, ms(10)) {
+                        break;
+                    }
+                }
+            }
+        });
+
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                if i % 2 == 0 {
+                    thread::sleep(ms(50));
+                }
+                loop {
+                    if let Ok(x) = r.recv_timeout(ms(10)) {
+                        assert_eq!(x, i);
+                        break;
+                    }
+                }
+            }
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn drops() {
+    const RUNS: usize = 100;
+
+    static DROPS: AtomicUsize = AtomicUsize::new(0);
+
+    #[derive(Debug, PartialEq)]
+    struct DropCounter;
+
+    impl Drop for DropCounter {
+        fn drop(&mut self) {
+            DROPS.fetch_add(1, Ordering::SeqCst);
+        }
+    }
+
+    let mut rng = thread_rng();
+
+    for _ in 0..RUNS {
+        let steps = rng.gen_range(0..10_000);
+        let additional = rng.gen_range(0..50);
+
+        DROPS.store(0, Ordering::SeqCst);
+        let (s, r) = bounded::<DropCounter>(50);
+
+        scope(|scope| {
+            scope.spawn(|_| {
+                for _ in 0..steps {
+                    r.recv().unwrap();
+                }
+            });
+
+            scope.spawn(|_| {
+                for _ in 0..steps {
+                    s.send(DropCounter).unwrap();
+                }
+            });
+        })
+        .unwrap();
+
+        for _ in 0..additional {
+            s.send(DropCounter).unwrap();
+        }
+
+        assert_eq!(DROPS.load(Ordering::SeqCst), steps);
+        drop(s);
+        drop(r);
+        assert_eq!(DROPS.load(Ordering::SeqCst), steps + additional);
+    }
+}
+
+#[test]
+fn linearizable() {
+    const COUNT: usize = 25_000;
+    const THREADS: usize = 4;
+
+    let (s, r) = bounded(THREADS);
+
+    scope(|scope| {
+        for _ in 0..THREADS {
+            scope.spawn(|_| {
+                for _ in 0..COUNT {
+                    s.send(0).unwrap();
+                    r.try_recv().unwrap();
+                }
+            });
+        }
+    })
+    .unwrap();
+}
+
+// #[test]
+// fn fairness() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded::<()>(COUNT);
+//     let (s2, r2) = bounded::<()>(COUNT);
+
+//     for _ in 0..COUNT {
+//         s1.send(()).unwrap();
+//         s2.send(()).unwrap();
+//     }
+
+//     let mut hits = [0usize; 2];
+//     for _ in 0..COUNT {
+//         select! {
+//             recv(r1) -> _  => hits[0] += 1,
+//             recv(r2) -> _  => hits[1] += 1,
+//         }
+//     }
+//     assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+// }
+
+// #[test]
+// fn fairness_duplicates() {
+//     const COUNT: usize = 10_000;
+
+//     let (s, r) = bounded::<()>(COUNT);
+
+//     for _ in 0..COUNT {
+//         s.send(()).unwrap();
+//     }
+
+//     let mut hits = [0usize; 5];
+//     for _ in 0..COUNT {
+//         select! {
+//             recv(r) -> _ => hits[0] += 1,
+//             recv(r) -> _ => hits[1] += 1,
+//             recv(r) -> _ => hits[2] += 1,
+//             recv(r) -> _ => hits[3] += 1,
+//             recv(r) -> _ => hits[4] += 1,
+//         }
+//     }
+//     assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+// }
+
+// #[test]
+// fn recv_in_send() {
+//     let (s, _r) = bounded(1);
+//     s.send(()).unwrap();
+
+//     #[allow(unreachable_code)]
+//     {
+//         select! {
+//             send(s, panic!()) -> _ => panic!(),
+//             default => {}
+//         }
+//     }
+
+//     let (s, r) = bounded(2);
+//     s.send(()).unwrap();
+
+//     select! {
+//         send(s, assert_eq!(r.recv(), Ok(()))) -> _ => {}
+//     }
+// }
+
+#[test]
+fn channel_through_channel() {
+    const COUNT: usize = 1000;
+
+    type T = Box<dyn Any + Send>;
+
+    let (s, r) = bounded::<T>(1);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            let mut s = s;
+
+            for _ in 0..COUNT {
+                let (new_s, new_r) = bounded(1);
+                let new_r: T = Box::new(Some(new_r));
+
+                s.send(new_r).unwrap();
+                s = new_s;
+            }
+        });
+
+        scope.spawn(move |_| {
+            let mut r = r;
+
+            for _ in 0..COUNT {
+                r = r
+                    .recv()
+                    .unwrap()
+                    .downcast_mut::<Option<Receiver<T>>>()
+                    .unwrap()
+                    .take()
+                    .unwrap()
+            }
+        });
+    })
+    .unwrap();
+}
diff --git a/vendor/flume/tests/async.rs b/vendor/flume/tests/async.rs
new file mode 100644
index 0000000..6c2c7f2
--- /dev/null
+++ b/vendor/flume/tests/async.rs
@@ -0,0 +1,276 @@
+#[cfg(feature = "async")]
+use {
+    flume::*,
+    futures::{stream::FuturesUnordered, StreamExt, TryFutureExt, Future},
+    futures::task::{Context, Waker, Poll},
+    async_std::prelude::FutureExt,
+    std::{time::Duration, sync::{atomic::{AtomicUsize, Ordering}, Arc}},
+};
+
+#[cfg(feature = "async")]
+#[test]
+fn r#async_recv() {
+    let (tx, rx) = unbounded();
+
+    let t = std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(250));
+        tx.send(42u32).unwrap();
+    });
+
+    async_std::task::block_on(async {
+        assert_eq!(rx.recv_async().await.unwrap(), 42);
+    });
+
+    t.join().unwrap();
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn r#async_send() {
+    let (tx, rx) = bounded(1);
+
+    let t = std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(250));
+        assert_eq!(rx.recv(), Ok(42));
+    });
+
+    async_std::task::block_on(async {
+        tx.send_async(42u32).await.unwrap();
+    });
+
+    t.join().unwrap();
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn r#async_recv_disconnect() {
+    let (tx, rx) = bounded::<i32>(0);
+
+    let t = std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(250));
+        drop(tx)
+    });
+
+    async_std::task::block_on(async {
+        assert_eq!(rx.recv_async().await, Err(RecvError::Disconnected));
+    });
+
+    t.join().unwrap();
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn r#async_send_disconnect() {
+    let (tx, rx) = bounded(0);
+
+    let t = std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(250));
+        drop(rx)
+    });
+
+    async_std::task::block_on(async {
+        assert_eq!(tx.send_async(42u32).await, Err(SendError(42)));
+    });
+
+    t.join().unwrap();
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn r#async_recv_drop_recv() {
+    let (tx, rx) = bounded::<i32>(10);
+
+    let recv_fut = rx.recv_async();
+
+    async_std::task::block_on(async {
+        let res = async_std::future::timeout(std::time::Duration::from_millis(500), rx.recv_async()).await;
+        assert!(res.is_err());
+    });
+
+    let rx2 = rx.clone();
+    let t = std::thread::spawn(move || {
+        async_std::task::block_on(async {
+            rx2.recv_async().await
+        })
+    });
+
+    std::thread::sleep(std::time::Duration::from_millis(500));
+
+    tx.send(42).unwrap();
+
+    drop(recv_fut);
+
+    assert_eq!(t.join().unwrap(), Ok(42))
+}
+
+#[cfg(feature = "async")]
+#[async_std::test]
+async fn r#async_send_1_million_no_drop_or_reorder() {
+    #[derive(Debug)]
+    enum Message {
+        Increment {
+            old: u64,
+        },
+        ReturnCount,
+    }
+
+    let (tx, rx) = unbounded();
+
+    let t = async_std::task::spawn(async move {
+        let mut count = 0u64;
+
+        while let Ok(Message::Increment { old }) = rx.recv_async().await {
+            assert_eq!(old, count);
+            count += 1;
+        }
+
+        count
+    });
+
+    for next in 0..1_000_000 {
+        tx.send(Message::Increment { old: next }).unwrap();
+    }
+
+    tx.send(Message::ReturnCount).unwrap();
+
+    let count = t.await;
+    assert_eq!(count, 1_000_000)
+}
+
+#[cfg(feature = "async")]
+#[async_std::test]
+async fn parallel_async_receivers() {
+    let (tx, rx) = flume::unbounded();
+    let send_fut = async move {
+        let n_sends: usize = 100000;
+        for _ in 0..n_sends {
+            tx.send_async(()).await.unwrap();
+        }
+    };
+
+    async_std::task::spawn(
+        send_fut
+            .timeout(Duration::from_secs(5))
+            .map_err(|_| panic!("Send timed out!"))
+    );
+
+    let mut futures_unordered = (0..250)
+        .map(|_| async {
+            while let Ok(()) = rx.recv_async().await
+            /* rx.recv() is OK */
+            {}
+        })
+        .collect::<FuturesUnordered<_>>();
+
+    let recv_fut = async {
+        while futures_unordered.next().await.is_some() {}
+    };
+
+    recv_fut
+        .timeout(Duration::from_secs(5))
+        .map_err(|_| panic!("Receive timed out!"))
+        .await
+        .unwrap();
+
+    println!("recv end");
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn change_waker() {
+    let (tx, rx) = flume::bounded(1);
+    tx.send(()).unwrap();
+
+    struct DebugWaker(Arc<AtomicUsize>, Waker);
+
+    impl DebugWaker {
+        fn new() -> Self {
+            let woken = Arc::new(AtomicUsize::new(0));
+            let woken_cloned = woken.clone();
+            let waker = waker_fn::waker_fn(move || {
+                woken.fetch_add(1, Ordering::SeqCst);
+            });
+            DebugWaker(woken_cloned, waker)
+        }
+
+        fn woken(&self) -> usize {
+            self.0.load(Ordering::SeqCst)
+        }
+
+        fn ctx(&self) -> Context {
+            Context::from_waker(&self.1)
+        }
+    }
+
+    // Check that the waker is correctly updated when sending tasks change their wakers
+    {
+        let send_fut = tx.send_async(());
+        futures::pin_mut!(send_fut);
+
+        let (waker1, waker2) = (DebugWaker::new(), DebugWaker::new());
+
+        // Set the waker to waker1
+        assert_eq!(send_fut.as_mut().poll(&mut waker1.ctx()), Poll::Pending);
+
+        // Change the waker to waker2
+        assert_eq!(send_fut.poll(&mut waker2.ctx()), Poll::Pending);
+
+        // Wake the future
+        rx.recv().unwrap();
+
+        // Check that waker2 was woken and waker1 was not
+        assert_eq!(waker1.woken(), 0);
+        assert_eq!(waker2.woken(), 1);
+    }
+
+    // Check that the waker is correctly updated when receiving tasks change their wakers
+    {
+        rx.recv().unwrap();
+        let recv_fut = rx.recv_async();
+        futures::pin_mut!(recv_fut);
+
+        let (waker1, waker2) = (DebugWaker::new(), DebugWaker::new());
+
+        // Set the waker to waker1
+        assert_eq!(recv_fut.as_mut().poll(&mut waker1.ctx()), Poll::Pending);
+
+        // Change the waker to waker2
+        assert_eq!(recv_fut.poll(&mut waker2.ctx()), Poll::Pending);
+
+        // Wake the future
+        tx.send(()).unwrap();
+
+        // Check that waker2 was woken and waker1 was not
+        assert_eq!(waker1.woken(), 0);
+        assert_eq!(waker2.woken(), 1);
+    }
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn spsc_single_threaded_value_ordering() {
+    async fn test() {
+        let (tx, rx) = flume::bounded(4);
+        tokio::select! {
+        _ = producer(tx) => {},
+        _ = consumer(rx) => {},
+    }
+    }
+
+    async fn producer(tx: flume::Sender<usize>) {
+        for i in 0..100 {
+            tx.send_async(i).await.unwrap();
+        }
+    }
+
+    async fn consumer(rx: flume::Receiver<usize>) {
+        let mut expected = 0;
+        while let Ok(value) = rx.recv_async().await {
+            assert_eq!(value, expected);
+            expected += 1;
+        }
+    }
+
+    let rt = tokio::runtime::Builder::new_current_thread().build().unwrap();
+    rt.block_on(test());
+}
diff --git a/vendor/flume/tests/basic.rs b/vendor/flume/tests/basic.rs
new file mode 100644
index 0000000..b937436
--- /dev/null
+++ b/vendor/flume/tests/basic.rs
@@ -0,0 +1,428 @@
+use std::time::{Instant, Duration};
+use flume::*;
+
+#[test]
+fn send_recv() {
+    let (tx, rx) = unbounded();
+    for i in 0..1000 { tx.send(i).unwrap(); }
+    for i in 0..1000 { assert_eq!(rx.try_recv().unwrap(), i); }
+    assert!(rx.try_recv().is_err());
+}
+
+#[test]
+fn iter() {
+    let (tx, rx) = unbounded();
+    for i in 0..1000 { tx.send(i).unwrap(); }
+    drop(tx);
+    assert_eq!(rx.iter().sum::<u32>(), (0..1000).sum());
+}
+
+#[test]
+fn try_iter() {
+    let (tx, rx) = unbounded();
+    for i in 0..1000 { tx.send(i).unwrap(); }
+    assert_eq!(rx.try_iter().sum::<u32>(), (0..1000).sum());
+}
+
+#[test]
+fn iter_threaded() {
+    let (tx, rx) = unbounded();
+    for i in 0..1000 {
+        let tx = tx.clone();
+        std::thread::spawn(move || tx.send(i).unwrap());
+    }
+    drop(tx);
+    assert_eq!(rx.iter().sum::<u32>(), (0..1000).sum());
+}
+
+#[cfg_attr(any(target_os = "macos", windows), ignore)] // FIXME #41
+#[test]
+fn send_timeout() {
+    let dur = Duration::from_millis(350);
+    let max_error = Duration::from_millis(5);
+    let dur_min = dur.checked_sub(max_error).unwrap();
+    let dur_max = dur.checked_add(max_error).unwrap();
+
+    let (tx, rx) = bounded(1);
+
+    assert!(tx.send_timeout(42, dur).is_ok());
+
+    let then = Instant::now();
+    assert!(tx.send_timeout(43, dur).is_err());
+    let now = Instant::now();
+
+    let this = now.duration_since(then);
+    if !(dur_min < this && this < dur_max) {
+        panic!("timeout exceeded: {:?}", this);
+    }
+
+    assert_eq!(rx.drain().count(), 1);
+
+    drop(rx);
+
+    assert!(tx.send_timeout(42, Duration::from_millis(350)).is_err());
+}
+
+#[cfg_attr(any(target_os = "macos", windows), ignore)] // FIXME #41
+#[test]
+fn recv_timeout() {
+    let dur = Duration::from_millis(350);
+    let max_error = Duration::from_millis(5);
+    let dur_min = dur.checked_sub(max_error).unwrap();
+    let dur_max = dur.checked_add(max_error).unwrap();
+
+    let (tx, rx) = unbounded();
+    let then = Instant::now();
+    assert!(rx.recv_timeout(dur).is_err());
+    let now = Instant::now();
+
+    let this = now.duration_since(then);
+    if !(dur_min < this && this < dur_max) {
+        panic!("timeout exceeded: {:?}", this);
+    }
+
+    tx.send(42).unwrap();
+    assert_eq!(rx.recv_timeout(dur), Ok(42));
+    assert!(Instant::now().duration_since(now) < max_error);
+}
+
+#[cfg_attr(any(target_os = "macos", windows), ignore)] // FIXME #41
+#[test]
+fn recv_deadline() {
+    let dur = Duration::from_millis(350);
+    let max_error = Duration::from_millis(5);
+    let dur_min = dur.checked_sub(max_error).unwrap();
+    let dur_max = dur.checked_add(max_error).unwrap();
+
+    let (tx, rx) = unbounded();
+    let then = Instant::now();
+    assert!(rx.recv_deadline(then.checked_add(dur).unwrap()).is_err());
+    let now = Instant::now();
+
+    let this = now.duration_since(then);
+    if !(dur_min < this && this < dur_max) {
+        panic!("timeout exceeded: {:?}", this);
+    }
+
+    tx.send(42).unwrap();
+    assert_eq!(rx.recv_deadline(now.checked_add(dur).unwrap()), Ok(42));
+    assert!(Instant::now().duration_since(now) < max_error);
+}
+
+#[test]
+fn recv_timeout_missed_send() {
+    let (tx, rx) = bounded(10);
+
+    assert!(rx.recv_timeout(Duration::from_millis(100)).is_err());
+
+    tx.send(42).unwrap();
+
+    assert_eq!(rx.recv(), Ok(42));
+}
+
+#[test]
+fn disconnect_tx() {
+    let (tx, rx) = unbounded::<()>();
+    drop(tx);
+    assert!(rx.recv().is_err());
+}
+
+#[test]
+fn disconnect_rx() {
+    let (tx, rx) = unbounded();
+    drop(rx);
+    assert!(tx.send(0).is_err());
+}
+
+#[test]
+fn drain() {
+    let (tx, rx) = unbounded();
+
+    for i in 0..100 {
+        tx.send(i).unwrap();
+    }
+
+    assert_eq!(rx.drain().sum::<u32>(), (0..100).sum());
+
+    for i in 0..100 {
+        tx.send(i).unwrap();
+    }
+
+    for i in 0..100 {
+        tx.send(i).unwrap();
+    }
+
+    rx.recv().unwrap();
+
+    (1u32..100).chain(0..100).zip(rx).for_each(|(l, r)| assert_eq!(l, r));
+}
+
+#[test]
+fn try_send() {
+    let (tx, rx) = bounded(5);
+
+    for i in 0..5 {
+        tx.try_send(i).unwrap();
+    }
+
+    assert!(tx.try_send(42).is_err());
+
+    assert_eq!(rx.recv(), Ok(0));
+
+    assert_eq!(tx.try_send(42), Ok(()));
+
+    assert_eq!(rx.recv(), Ok(1));
+    drop(rx);
+
+    assert!(tx.try_send(42).is_err());
+}
+
+#[test]
+fn send_bounded() {
+    let (tx, rx) = bounded(5);
+
+    for _ in 0..5 {
+        tx.send(42).unwrap();
+    }
+
+    let _ = rx.recv().unwrap();
+
+    tx.send(42).unwrap();
+
+    assert!(tx.try_send(42).is_err());
+
+    rx.drain();
+
+    let mut ts = Vec::new();
+    for _ in 0..100 {
+        let tx = tx.clone();
+        ts.push(std::thread::spawn(move || {
+            for i in 0..10000 {
+                tx.send(i).unwrap();
+            }
+        }));
+    }
+
+    drop(tx);
+
+    assert_eq!(rx.iter().sum::<u64>(), (0..10000).sum::<u64>() * 100);
+
+    for t in ts {
+        t.join().unwrap();
+    }
+
+    assert!(rx.recv().is_err());
+}
+
+#[test]
+fn rendezvous() {
+    let (tx, rx) = bounded(0);
+
+    for i in 0..5 {
+        let tx = tx.clone();
+        let t = std::thread::spawn(move || {
+            assert!(tx.try_send(()).is_err());
+
+            let then = Instant::now();
+            tx.send(()).unwrap();
+            let now = Instant::now();
+
+            assert!(now.duration_since(then) > Duration::from_millis(100), "iter = {}", i);
+        });
+
+        std::thread::sleep(Duration::from_millis(1000));
+        rx.recv().unwrap();
+
+        t.join().unwrap();
+    }
+}
+
+#[test]
+fn hydra() {
+    let thread_num = 32;
+    let msg_num = 1000;
+
+    let (main_tx, main_rx) = unbounded::<()>();
+
+    let mut txs = Vec::new();
+    for _ in 0..thread_num {
+        let main_tx = main_tx.clone();
+        let (tx, rx) = unbounded();
+        txs.push(tx);
+
+        std::thread::spawn(move || {
+            for msg in rx.iter() {
+                main_tx.send(msg).unwrap();
+            }
+        });
+    }
+
+    drop(main_tx);
+
+    for _ in 0..10 {
+        for tx in &txs {
+            for _ in 0..msg_num {
+                tx.send(Default::default()).unwrap();
+            }
+        }
+
+        for _ in 0..thread_num {
+            for _ in 0..msg_num {
+                main_rx.recv().unwrap();
+            }
+        }
+    }
+
+    drop(txs);
+    assert!(main_rx.recv().is_err());
+}
+
+#[test]
+fn robin() {
+    let thread_num = 32;
+    let msg_num = 10;
+
+    let (mut main_tx, main_rx) = bounded::<()>(1);
+
+    for _ in 0..thread_num {
+        let (mut tx, rx) = bounded(100);
+        std::mem::swap(&mut tx, &mut main_tx);
+
+        std::thread::spawn(move || {
+            for msg in rx.iter() {
+                tx.send(msg).unwrap();
+            }
+        });
+    }
+
+    for _ in 0..10 {
+        let main_tx = main_tx.clone();
+        std::thread::spawn(move || {
+            for _ in 0..msg_num {
+                main_tx.send(Default::default()).unwrap();
+            }
+        });
+
+        for _ in 0..msg_num {
+            main_rx.recv().unwrap();
+        }
+    }
+}
+
+#[cfg(feature = "select")]
+#[test]
+fn select_general() {
+    #[derive(Debug, PartialEq)]
+    struct Foo(usize);
+
+    let (tx0, rx0) = bounded(1);
+    let (tx1, rx1) = unbounded();
+
+    for (i, t) in vec![tx0.clone(), tx1].into_iter().enumerate() {
+        std::thread::spawn(move || {
+            std::thread::sleep(std::time::Duration::from_millis(250));
+            let _ = t.send(Foo(i));
+        });
+    }
+
+    let x = Selector::new()
+        .recv(&rx0, |x| x)
+        .recv(&rx1, |x| x)
+        .wait()
+        .unwrap();
+
+    if x == Foo(0) {
+        assert!(rx1.recv().unwrap() == Foo(1));
+    } else {
+        assert!(rx0.recv().unwrap() == Foo(0));
+    }
+
+    tx0.send(Foo(42)).unwrap();
+
+    let t = std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(100));
+        assert_eq!(rx0.recv().unwrap(), Foo(42));
+        assert_eq!(rx0.recv().unwrap(), Foo(43));
+
+    });
+
+    Selector::new()
+        .send(&tx0, Foo(43), |x| x)
+        .wait()
+        .unwrap();
+
+    t.join().unwrap();
+}
+
+struct MessageWithoutDebug(u32);
+
+#[test]
+// This is a 'does it build' test, to make sure that the error types can turn
+// into a std::error::Error without requiring the payload (which is not used
+// there) to impl Debug.
+fn std_error_without_debug() {
+    let (tx, rx) = unbounded::<MessageWithoutDebug>();
+
+    match tx.send(MessageWithoutDebug(1)) {
+        Ok(_) => {}
+        Err(e) => {
+            let _std_err: &dyn std::error::Error = &e;
+        }
+    }
+
+    match rx.recv() {
+        Ok(_) => {}
+        Err(e) => {
+            let _std_err: &dyn std::error::Error = &e;
+        }
+    }
+
+    match tx.try_send(MessageWithoutDebug(2)) {
+        Ok(_) => {}
+        Err(e) => {
+            let _std_err: &dyn std::error::Error = &e;
+        }
+    }
+
+    match rx.try_recv() {
+        Ok(_) => {}
+        Err(e) => {
+            let _std_err: &dyn std::error::Error = &e;
+        }
+    }
+
+    match tx.send_timeout(MessageWithoutDebug(3), Duration::from_secs(1000000)) {
+        Ok(_) => {}
+        Err(e) => {
+            let _std_err: &dyn std::error::Error = &e;
+        }
+    }
+
+    match rx.recv_timeout(Duration::from_secs(10000000)) {
+        Ok(_) => {}
+        Err(e) => {
+            let _std_err: &dyn std::error::Error = &e;
+        }
+    }
+}
+
+#[test]
+fn weak_close() {
+    let (tx, rx) = unbounded::<()>();
+    let weak = tx.downgrade();
+    drop(tx);
+    assert!(weak.upgrade().is_none());
+    assert!(rx.is_disconnected());
+    assert!(rx.try_recv().is_err());
+}
+
+#[test]
+fn weak_upgrade() {
+    let (tx, rx) = unbounded();
+    let weak = tx.downgrade();
+    let tx2 = weak.upgrade().unwrap();
+    drop(tx);
+    assert!(!rx.is_disconnected());
+    tx2.send(()).unwrap();
+    assert!(rx.try_recv().is_ok());
+}
diff --git a/vendor/flume/tests/check_same_channel.rs b/vendor/flume/tests/check_same_channel.rs
new file mode 100644
index 0000000..edb82c3
--- /dev/null
+++ b/vendor/flume/tests/check_same_channel.rs
@@ -0,0 +1,57 @@
+#[test]
+fn same_sender() {
+    let (tx1, _rx) = flume::unbounded::<()>();
+    let tx2 = tx1.clone();
+
+    assert!(tx1.same_channel(&tx2));
+
+    let (tx3, _rx) = flume::unbounded::<()>();
+
+    assert!(!tx1.same_channel(&tx3));
+    assert!(!tx2.same_channel(&tx3));
+}
+
+#[test]
+fn same_receiver() {
+    let (_tx, rx1) = flume::unbounded::<()>();
+    let rx2 = rx1.clone();
+
+    assert!(rx1.same_channel(&rx2));
+
+    let (_tx, rx3) = flume::unbounded::<()>();
+
+    assert!(!rx1.same_channel(&rx3));
+    assert!(!rx2.same_channel(&rx3));
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn same_send_sink() {
+    let (tx1, _rx) = flume::unbounded::<()>();
+    let tx1 = tx1.into_sink();
+    let tx2 = tx1.clone();
+
+    assert!(tx1.same_channel(&tx2));
+
+    let (tx3, _rx) = flume::unbounded::<()>();
+    let tx3 = tx3.into_sink();
+
+    assert!(!tx1.same_channel(&tx3));
+    assert!(!tx2.same_channel(&tx3));
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn same_recv_stream() {
+    let (_tx, rx1) = flume::unbounded::<()>();
+    let rx1 = rx1.into_stream();
+    let rx2 = rx1.clone();
+
+    assert!(rx1.same_channel(&rx2));
+
+    let (_tx, rx3) = flume::unbounded::<()>();
+    let rx3 = rx3.into_stream();
+
+    assert!(!rx1.same_channel(&rx3));
+    assert!(!rx2.same_channel(&rx3));
+}
diff --git a/vendor/flume/tests/golang.rs b/vendor/flume/tests/golang.rs
new file mode 100644
index 0000000..ca00840
--- /dev/null
+++ b/vendor/flume/tests/golang.rs
@@ -0,0 +1,1445 @@
+// //! Tests copied from Go and manually rewritten in Rust.
+// //!
+// //! Source:
+// //!   - https://github.com/golang/go
+// //!
+// //! Copyright & License:
+// //!   - Copyright (c) 2009 The Go Authors
+// //!   - https://golang.org/AUTHORS
+// //!   - https://golang.org/LICENSE
+// //!   - https://golang.org/PATENTS
+
+// use std::any::Any;
+// use std::cell::Cell;
+// use std::collections::HashMap;
+// use std::sync::{Arc, Condvar, Mutex};
+// use std::thread;
+// use std::time::Duration;
+
+// use flume::{bounded, tick, Receiver, Select, Sender};
+
+// fn ms(ms: u64) -> Duration {
+//     Duration::from_millis(ms)
+// }
+
+// struct Chan<T> {
+//     inner: Arc<Mutex<ChanInner<T>>>,
+// }
+
+// struct ChanInner<T> {
+//     s: Option<Sender<T>>,
+//     r: Receiver<T>,
+// }
+
+// impl<T> Clone for Chan<T> {
+//     fn clone(&self) -> Chan<T> {
+//         Chan {
+//             inner: self.inner.clone(),
+//         }
+//     }
+// }
+
+// impl<T> Chan<T> {
+//     fn send(&self, msg: T) {
+//         let s = self
+//             .inner
+//             .lock()
+//             .unwrap()
+//             .s
+//             .as_ref()
+//             .expect("sending into closed channel")
+//             .clone();
+//         let _ = s.send(msg);
+//     }
+
+//     fn try_recv(&self) -> Option<T> {
+//         let r = self.inner.lock().unwrap().r.clone();
+//         r.try_recv().ok()
+//     }
+
+//     fn recv(&self) -> Option<T> {
+//         let r = self.inner.lock().unwrap().r.clone();
+//         r.recv().ok()
+//     }
+
+//     fn close(&self) {
+//         self.inner
+//             .lock()
+//             .unwrap()
+//             .s
+//             .take()
+//             .expect("channel already closed");
+//     }
+
+//     fn rx(&self) -> Receiver<T> {
+//         self.inner.lock().unwrap().r.clone()
+//     }
+
+//     fn tx(&self) -> Sender<T> {
+//         match self.inner.lock().unwrap().s.as_ref() {
+//             None => {
+//                 let (s, r) = bounded(0);
+//                 std::mem::forget(r);
+//                 s
+//             }
+//             Some(s) => s.clone(),
+//         }
+//     }
+// }
+
+// impl<T> Iterator for Chan<T> {
+//     type Item = T;
+
+//     fn next(&mut self) -> Option<Self::Item> {
+//         self.recv()
+//     }
+// }
+
+// impl<'a, T> IntoIterator for &'a Chan<T> {
+//     type Item = T;
+//     type IntoIter = Chan<T>;
+
+//     fn into_iter(self) -> Self::IntoIter {
+//         self.clone()
+//     }
+// }
+
+// fn make<T>(cap: usize) -> Chan<T> {
+//     let (s, r) = bounded(cap);
+//     Chan {
+//         inner: Arc::new(Mutex::new(ChanInner { s: Some(s), r })),
+//     }
+// }
+
+// #[derive(Clone)]
+// struct WaitGroup(Arc<WaitGroupInner>);
+
+// struct WaitGroupInner {
+//     cond: Condvar,
+//     count: Mutex<i32>,
+// }
+
+// impl WaitGroup {
+//     fn new() -> WaitGroup {
+//         WaitGroup(Arc::new(WaitGroupInner {
+//             cond: Condvar::new(),
+//             count: Mutex::new(0),
+//         }))
+//     }
+
+//     fn add(&self, delta: i32) {
+//         let mut count = self.0.count.lock().unwrap();
+//         *count += delta;
+//         assert!(*count >= 0);
+//         self.0.cond.notify_all();
+//     }
+
+//     fn done(&self) {
+//         self.add(-1);
+//     }
+
+//     fn wait(&self) {
+//         let mut count = self.0.count.lock().unwrap();
+//         while *count > 0 {
+//             count = self.0.cond.wait(count).unwrap();
+//         }
+//     }
+// }
+
+// struct Defer<F: FnOnce()> {
+//     f: Option<Box<F>>,
+// }
+
+// impl<F: FnOnce()> Drop for Defer<F> {
+//     fn drop(&mut self) {
+//         let f = self.f.take().unwrap();
+//         let mut f = Some(f);
+//         let mut f = move || f.take().unwrap()();
+//         f();
+//     }
+// }
+
+// macro_rules! defer {
+//     ($body:expr) => {
+//         let _defer = Defer {
+//             f: Some(Box::new(|| $body)),
+//         };
+//     };
+// }
+
+// macro_rules! go {
+//     (@parse ref $v:ident, $($tail:tt)*) => {{
+//         let ref $v = $v;
+//         go!(@parse $($tail)*)
+//     }};
+//     (@parse move $v:ident, $($tail:tt)*) => {{
+//         let $v = $v;
+//         go!(@parse $($tail)*)
+//     }};
+//     (@parse $v:ident, $($tail:tt)*) => {{
+//         let $v = $v.clone();
+//         go!(@parse $($tail)*)
+//     }};
+//     (@parse $body:expr) => {
+//         ::std::thread::spawn(move || {
+//             let res = ::std::panic::catch_unwind(::std::panic::AssertUnwindSafe(|| {
+//                 $body
+//             }));
+//             if res.is_err() {
+//                 eprintln!("goroutine panicked: {:?}", res);
+//                 ::std::process::abort();
+//             }
+//         })
+//     };
+//     (@parse $($tail:tt)*) => {
+//         compile_error!("invalid `go!` syntax")
+//     };
+//     ($($tail:tt)*) => {{
+//         go!(@parse $($tail)*)
+//     }};
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/doubleselect.go
+// mod doubleselect {
+//     use super::*;
+
+//     const ITERATIONS: i32 = 10_000;
+
+//     fn sender(n: i32, c1: Chan<i32>, c2: Chan<i32>, c3: Chan<i32>, c4: Chan<i32>) {
+//         defer! { c1.close() }
+//         defer! { c2.close() }
+//         defer! { c3.close() }
+//         defer! { c4.close() }
+
+//         for i in 0..n {
+//             select! {
+//                 send(c1.tx(), i) -> _ => {}
+//                 send(c2.tx(), i) -> _ => {}
+//                 send(c3.tx(), i) -> _ => {}
+//                 send(c4.tx(), i) -> _ => {}
+//             }
+//         }
+//     }
+
+//     fn mux(out: Chan<i32>, inp: Chan<i32>, done: Chan<bool>) {
+//         for v in inp {
+//             out.send(v);
+//         }
+//         done.send(true);
+//     }
+
+//     fn recver(inp: Chan<i32>) {
+//         let mut seen = HashMap::new();
+
+//         for v in &inp {
+//             if seen.contains_key(&v) {
+//                 panic!("got duplicate value for {}", v);
+//             }
+//             seen.insert(v, true);
+//         }
+//     }
+
+//     #[test]
+//     fn main() {
+//         let c1 = make::<i32>(0);
+//         let c2 = make::<i32>(0);
+//         let c3 = make::<i32>(0);
+//         let c4 = make::<i32>(0);
+//         let done = make::<bool>(0);
+//         let cmux = make::<i32>(0);
+
+//         go!(c1, c2, c3, c4, sender(ITERATIONS, c1, c2, c3, c4));
+//         go!(cmux, c1, done, mux(cmux, c1, done));
+//         go!(cmux, c2, done, mux(cmux, c2, done));
+//         go!(cmux, c3, done, mux(cmux, c3, done));
+//         go!(cmux, c4, done, mux(cmux, c4, done));
+//         go!(done, cmux, {
+//             done.recv();
+//             done.recv();
+//             done.recv();
+//             done.recv();
+//             cmux.close();
+//         });
+//         recver(cmux);
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/fifo.go
+// mod fifo {
+//     use super::*;
+
+//     const N: i32 = 10;
+
+//     #[test]
+//     fn asynch_fifo() {
+//         let ch = make::<i32>(N as usize);
+//         for i in 0..N {
+//             ch.send(i);
+//         }
+//         for i in 0..N {
+//             if ch.recv() != Some(i) {
+//                 panic!("bad receive");
+//             }
+//         }
+//     }
+
+//     fn chain(ch: Chan<i32>, val: i32, inp: Chan<i32>, out: Chan<i32>) {
+//         inp.recv();
+//         if ch.recv() != Some(val) {
+//             panic!(val);
+//         }
+//         out.send(1);
+//     }
+
+//     #[test]
+//     fn synch_fifo() {
+//         let ch = make::<i32>(0);
+//         let mut inp = make::<i32>(0);
+//         let start = inp.clone();
+
+//         for i in 0..N {
+//             let out = make::<i32>(0);
+//             go!(ch, i, inp, out, chain(ch, i, inp, out));
+//             inp = out;
+//         }
+
+//         start.send(0);
+//         for i in 0..N {
+//             ch.send(i);
+//         }
+//         inp.recv();
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/goroutines.go
+// mod goroutines {
+//     use super::*;
+
+//     fn f(left: Chan<i32>, right: Chan<i32>) {
+//         left.send(right.recv().unwrap());
+//     }
+
+//     #[test]
+//     fn main() {
+//         let n = 100i32;
+
+//         let leftmost = make::<i32>(0);
+//         let mut right = leftmost.clone();
+//         let mut left = leftmost.clone();
+
+//         for _ in 0..n {
+//             right = make::<i32>(0);
+//             go!(left, right, f(left, right));
+//             left = right.clone();
+//         }
+
+//         go!(right, right.send(1));
+//         leftmost.recv().unwrap();
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/nonblock.go
+// mod nonblock {
+//     use super::*;
+
+//     fn i32receiver(c: Chan<i32>, strobe: Chan<bool>) {
+//         if c.recv().unwrap() != 123 {
+//             panic!("i32 value");
+//         }
+//         strobe.send(true);
+//     }
+
+//     fn i32sender(c: Chan<i32>, strobe: Chan<bool>) {
+//         c.send(234);
+//         strobe.send(true);
+//     }
+
+//     fn i64receiver(c: Chan<i64>, strobe: Chan<bool>) {
+//         if c.recv().unwrap() != 123456 {
+//             panic!("i64 value");
+//         }
+//         strobe.send(true);
+//     }
+
+//     fn i64sender(c: Chan<i64>, strobe: Chan<bool>) {
+//         c.send(234567);
+//         strobe.send(true);
+//     }
+
+//     fn breceiver(c: Chan<bool>, strobe: Chan<bool>) {
+//         if !c.recv().unwrap() {
+//             panic!("b value");
+//         }
+//         strobe.send(true);
+//     }
+
+//     fn bsender(c: Chan<bool>, strobe: Chan<bool>) {
+//         c.send(true);
+//         strobe.send(true);
+//     }
+
+//     fn sreceiver(c: Chan<String>, strobe: Chan<bool>) {
+//         if c.recv().unwrap() != "hello" {
+//             panic!("x value");
+//         }
+//         strobe.send(true);
+//     }
+
+//     fn ssender(c: Chan<String>, strobe: Chan<bool>) {
+//         c.send("hello again".to_string());
+//         strobe.send(true);
+//     }
+
+//     const MAX_TRIES: usize = 10000; // Up to 100ms per test.
+
+//     #[test]
+//     fn main() {
+//         let ticker = tick(Duration::new(0, 10_000)); // 10 us
+//         let sleep = || {
+//             ticker.recv().unwrap();
+//             ticker.recv().unwrap();
+//             thread::yield_now();
+//             thread::yield_now();
+//             thread::yield_now();
+//         };
+
+//         let sync = make::<bool>(0);
+
+//         for buffer in 0..2 {
+//             let c32 = make::<i32>(buffer);
+//             let c64 = make::<i64>(buffer);
+//             let cb = make::<bool>(buffer);
+//             let cs = make::<String>(buffer);
+
+//             select! {
+//                 recv(c32.rx()) -> _ => panic!("blocked i32sender"),
+//                 default => {}
+//             }
+
+//             select! {
+//                 recv(c64.rx()) -> _ => panic!("blocked i64sender"),
+//                 default => {}
+//             }
+
+//             select! {
+//                 recv(cb.rx()) -> _ => panic!("blocked bsender"),
+//                 default => {}
+//             }
+
+//             select! {
+//                 recv(cs.rx()) -> _ => panic!("blocked ssender"),
+//                 default => {}
+//             }
+
+//             go!(c32, sync, i32receiver(c32, sync));
+//             let mut try = 0;
+//             loop {
+//                 select! {
+//                     send(c32.tx(), 123) -> _ => break,
+//                     default => {
+//                         try += 1;
+//                         if try > MAX_TRIES {
+//                             println!("i32receiver buffer={}", buffer);
+//                             panic!("fail")
+//                         }
+//                         sleep();
+//                     }
+//                 }
+//             }
+//             sync.recv();
+//             go!(c32, sync, i32sender(c32, sync));
+//             if buffer > 0 {
+//                 sync.recv();
+//             }
+//             let mut try = 0;
+//             loop {
+//                 select! {
+//                     recv(c32.rx()) -> v => {
+//                         if v != Ok(234) {
+//                             panic!("i32sender value");
+//                         }
+//                         break;
+//                     }
+//                     default => {
+//                         try += 1;
+//                         if try > MAX_TRIES {
+//                             println!("i32sender buffer={}", buffer);
+//                             panic!("fail");
+//                         }
+//                         sleep();
+//                     }
+//                 }
+//             }
+//             if buffer == 0 {
+//                 sync.recv();
+//             }
+
+//             go!(c64, sync, i64receiver(c64, sync));
+//             let mut try = 0;
+//             loop {
+//                 select! {
+//                     send(c64.tx(), 123456) -> _ => break,
+//                     default => {
+//                         try += 1;
+//                         if try > MAX_TRIES {
+//                             println!("i64receiver buffer={}", buffer);
+//                             panic!("fail")
+//                         }
+//                         sleep();
+//                     }
+//                 }
+//             }
+//             sync.recv();
+//             go!(c64, sync, i64sender(c64, sync));
+//             if buffer > 0 {
+//                 sync.recv();
+//             }
+//             let mut try = 0;
+//             loop {
+//                 select! {
+//                     recv(c64.rx()) -> v => {
+//                         if v != Ok(234567) {
+//                             panic!("i64sender value");
+//                         }
+//                         break;
+//                     }
+//                     default => {
+//                         try += 1;
+//                         if try > MAX_TRIES {
+//                             println!("i64sender buffer={}", buffer);
+//                             panic!("fail");
+//                         }
+//                         sleep();
+//                     }
+//                 }
+//             }
+//             if buffer == 0 {
+//                 sync.recv();
+//             }
+
+//             go!(cb, sync, breceiver(cb, sync));
+//             let mut try = 0;
+//             loop {
+//                 select! {
+//                     send(cb.tx(), true) -> _ => break,
+//                     default => {
+//                         try += 1;
+//                         if try > MAX_TRIES {
+//                             println!("breceiver buffer={}", buffer);
+//                             panic!("fail")
+//                         }
+//                         sleep();
+//                     }
+//                 }
+//             }
+//             sync.recv();
+//             go!(cb, sync, bsender(cb, sync));
+//             if buffer > 0 {
+//                 sync.recv();
+//             }
+//             let mut try = 0;
+//             loop {
+//                 select! {
+//                     recv(cb.rx()) -> v => {
+//                         if v != Ok(true) {
+//                             panic!("bsender value");
+//                         }
+//                         break;
+//                     }
+//                     default => {
+//                         try += 1;
+//                         if try > MAX_TRIES {
+//                             println!("bsender buffer={}", buffer);
+//                             panic!("fail");
+//                         }
+//                         sleep();
+//                     }
+//                 }
+//             }
+//             if buffer == 0 {
+//                 sync.recv();
+//             }
+
+//             go!(cs, sync, sreceiver(cs, sync));
+//             let mut try = 0;
+//             loop {
+//                 select! {
+//                     send(cs.tx(), "hello".to_string()) -> _ => break,
+//                     default => {
+//                         try += 1;
+//                         if try > MAX_TRIES {
+//                             println!("sreceiver buffer={}", buffer);
+//                             panic!("fail")
+//                         }
+//                         sleep();
+//                     }
+//                 }
+//             }
+//             sync.recv();
+//             go!(cs, sync, ssender(cs, sync));
+//             if buffer > 0 {
+//                 sync.recv();
+//             }
+//             let mut try = 0;
+//             loop {
+//                 select! {
+//                     recv(cs.rx()) -> v => {
+//                         if v != Ok("hello again".to_string()) {
+//                             panic!("ssender value");
+//                         }
+//                         break;
+//                     }
+//                     default => {
+//                         try += 1;
+//                         if try > MAX_TRIES {
+//                             println!("ssender buffer={}", buffer);
+//                             panic!("fail");
+//                         }
+//                         sleep();
+//                     }
+//                 }
+//             }
+//             if buffer == 0 {
+//                 sync.recv();
+//             }
+//         }
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/select.go
+// mod select {
+//     use super::*;
+
+//     #[test]
+//     fn main() {
+//         let shift = Cell::new(0);
+//         let counter = Cell::new(0);
+
+//         let get_value = || {
+//             counter.set(counter.get() + 1);
+//             1 << shift.get()
+//         };
+
+//         let send = |mut a: Option<&Chan<u32>>, mut b: Option<&Chan<u32>>| {
+//             let mut i = 0;
+//             let never = make::<u32>(0);
+//             loop {
+//                 let nil1 = never.tx();
+//                 let nil2 = never.tx();
+//                 let v1 = get_value();
+//                 let v2 = get_value();
+//                 select! {
+//                     send(a.map(|c| c.tx()).unwrap_or(nil1), v1) -> _ => {
+//                         i += 1;
+//                         a = None;
+//                     }
+//                     send(b.map(|c| c.tx()).unwrap_or(nil2), v2) -> _ => {
+//                         i += 1;
+//                         b = None;
+//                     }
+//                     default => break,
+//                 }
+//                 shift.set(shift.get() + 1);
+//             }
+//             i
+//         };
+
+//         let a = make::<u32>(1);
+//         let b = make::<u32>(1);
+
+//         assert_eq!(send(Some(&a), Some(&b)), 2);
+
+//         let av = a.recv().unwrap();
+//         let bv = b.recv().unwrap();
+//         assert_eq!(av | bv, 3);
+
+//         assert_eq!(send(Some(&a), None), 1);
+//         assert_eq!(counter.get(), 10);
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/select2.go
+// mod select2 {
+//     // TODO
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/select3.go
+// mod select3 {
+//     // TODO
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/select4.go
+// mod select4 {
+//     use super::*;
+
+//     #[test]
+//     fn main() {
+//         let c = make::<i32>(1);
+//         let c1 = make::<i32>(0);
+//         c.send(42);
+//         select! {
+//             recv(c1.rx()) -> _ => panic!("BUG"),
+//             recv(c.rx()) -> v => assert_eq!(v, Ok(42)),
+//         }
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/select6.go
+// mod select6 {
+//     use super::*;
+
+//     #[test]
+//     fn main() {
+//         let c1 = make::<bool>(0);
+//         let c2 = make::<bool>(0);
+//         let c3 = make::<bool>(0);
+
+//         go!(c1, c1.recv());
+//         go!(c1, c2, c3, {
+//             select! {
+//                 recv(c1.rx()) -> _ => panic!("dummy"),
+//                 recv(c2.rx()) -> _ => c3.send(true),
+//             }
+//             c1.recv();
+//         });
+//         go!(c2, c2.send(true));
+
+//         c3.recv();
+//         c1.send(true);
+//         c1.send(true);
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/select7.go
+// mod select7 {
+//     use super::*;
+
+//     fn recv1(c: Chan<i32>) {
+//         c.recv().unwrap();
+//     }
+
+//     fn recv2(c: Chan<i32>) {
+//         select! {
+//             recv(c.rx()) -> _ => ()
+//         }
+//     }
+
+//     fn recv3(c: Chan<i32>) {
+//         let c2 = make::<i32>(1);
+//         select! {
+//             recv(c.rx()) -> _ => (),
+//             recv(c2.rx()) -> _ => ()
+//         }
+//     }
+
+//     fn send1(recv: fn(Chan<i32>)) {
+//         let c = make::<i32>(1);
+//         go!(c, recv(c));
+//         thread::yield_now();
+//         c.send(1);
+//     }
+
+//     fn send2(recv: fn(Chan<i32>)) {
+//         let c = make::<i32>(1);
+//         go!(c, recv(c));
+//         thread::yield_now();
+//         select! {
+//             send(c.tx(), 1) -> _ => ()
+//         }
+//     }
+
+//     fn send3(recv: fn(Chan<i32>)) {
+//         let c = make::<i32>(1);
+//         go!(c, recv(c));
+//         thread::yield_now();
+//         let c2 = make::<i32>(1);
+//         select! {
+//             send(c.tx(), 1) -> _ => (),
+//             send(c2.tx(), 1) -> _ => ()
+//         }
+//     }
+
+//     #[test]
+//     fn main() {
+//         send1(recv1);
+//         send2(recv1);
+//         send3(recv1);
+//         send1(recv2);
+//         send2(recv2);
+//         send3(recv2);
+//         send1(recv3);
+//         send2(recv3);
+//         send3(recv3);
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/sieve1.go
+// mod sieve1 {
+//     use super::*;
+
+//     fn generate(ch: Chan<i32>) {
+//         let mut i = 2;
+//         loop {
+//             ch.send(i);
+//             i += 1;
+//         }
+//     }
+
+//     fn filter(in_ch: Chan<i32>, out_ch: Chan<i32>, prime: i32) {
+//         for i in in_ch {
+//             if i % prime != 0 {
+//                 out_ch.send(i);
+//             }
+//         }
+//     }
+
+//     fn sieve(primes: Chan<i32>) {
+//         let mut ch = make::<i32>(1);
+//         go!(ch, generate(ch));
+//         loop {
+//             let prime = ch.recv().unwrap();
+//             primes.send(prime);
+
+//             let ch1 = make::<i32>(1);
+//             go!(ch, ch1, prime, filter(ch, ch1, prime));
+//             ch = ch1;
+//         }
+//     }
+
+//     #[test]
+//     fn main() {
+//         let primes = make::<i32>(1);
+//         go!(primes, sieve(primes));
+
+//         let a = [
+//             2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83,
+//             89, 97,
+//         ];
+//         for item in a.iter() {
+//             let x = primes.recv().unwrap();
+//             if x != *item {
+//                 println!("{} != {}", x, item);
+//                 panic!("fail");
+//             }
+//         }
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/chan/zerosize.go
+// mod zerosize {
+//     use super::*;
+
+//     #[test]
+//     fn zero_size_struct() {
+//         struct ZeroSize;
+//         let _ = make::<ZeroSize>(0);
+//     }
+
+//     #[test]
+//     fn zero_size_array() {
+//         let _ = make::<[u8; 0]>(0);
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/src/runtime/chan_test.go
+// mod chan_test {
+//     use super::*;
+
+//     #[test]
+//     fn test_chan() {
+//         const N: i32 = 200;
+
+//         for cap in 0..N {
+//             {
+//                 // Ensure that receive from empty chan blocks.
+//                 let c = make::<i32>(cap as usize);
+
+//                 let recv1 = Arc::new(Mutex::new(false));
+//                 go!(c, recv1, {
+//                     c.recv();
+//                     *recv1.lock().unwrap() = true;
+//                 });
+
+//                 let recv2 = Arc::new(Mutex::new(false));
+//                 go!(c, recv2, {
+//                     c.recv();
+//                     *recv2.lock().unwrap() = true;
+//                 });
+
+//                 thread::sleep(ms(1));
+
+//                 if *recv1.lock().unwrap() || *recv2.lock().unwrap() {
+//                     panic!();
+//                 }
+
+//                 // Ensure that non-blocking receive does not block.
+//                 select! {
+//                     recv(c.rx()) -> _ => panic!(),
+//                     default => {}
+//                 }
+//                 select! {
+//                     recv(c.rx()) -> _ => panic!(),
+//                     default => {}
+//                 }
+
+//                 c.send(0);
+//                 c.send(0);
+//             }
+
+//             {
+//                 // Ensure that send to full chan blocks.
+//                 let c = make::<i32>(cap as usize);
+//                 for i in 0..cap {
+//                     c.send(i);
+//                 }
+
+//                 let sent = Arc::new(Mutex::new(0));
+//                 go!(sent, c, {
+//                     c.send(0);
+//                     *sent.lock().unwrap() = 1;
+//                 });
+
+//                 thread::sleep(ms(1));
+
+//                 if *sent.lock().unwrap() != 0 {
+//                     panic!();
+//                 }
+
+//                 // Ensure that non-blocking send does not block.
+//                 select! {
+//                     send(c.tx(), 0) -> _ => panic!(),
+//                     default => {}
+//                 }
+//                 c.recv();
+//             }
+
+//             {
+//                 // Ensure that we receive 0 from closed chan.
+//                 let c = make::<i32>(cap as usize);
+//                 for i in 0..cap {
+//                     c.send(i);
+//                 }
+//                 c.close();
+
+//                 for i in 0..cap {
+//                     let v = c.recv();
+//                     if v != Some(i) {
+//                         panic!();
+//                     }
+//                 }
+
+//                 if c.recv() != None {
+//                     panic!();
+//                 }
+//                 if c.try_recv() != None {
+//                     panic!();
+//                 }
+//             }
+
+//             {
+//                 // Ensure that close unblocks receive.
+//                 let c = make::<i32>(cap as usize);
+//                 let done = make::<bool>(0);
+
+//                 go!(c, done, {
+//                     let v = c.try_recv();
+//                     done.send(v.is_some());
+//                 });
+
+//                 thread::sleep(ms(1));
+//                 c.close();
+
+//                 if !done.recv().unwrap() {
+//                     // panic!();
+//                 }
+//             }
+
+//             {
+//                 // Send 100 integers,
+//                 // ensure that we receive them non-corrupted in FIFO order.
+//                 let c = make::<i32>(cap as usize);
+//                 go!(c, {
+//                     for i in 0..100 {
+//                         c.send(i);
+//                     }
+//                 });
+//                 for i in 0..100 {
+//                     if c.recv() != Some(i) {
+//                         panic!();
+//                     }
+//                 }
+
+//                 // Same, but using recv2.
+//                 go!(c, {
+//                     for i in 0..100 {
+//                         c.send(i);
+//                     }
+//                 });
+//                 for i in 0..100 {
+//                     if c.recv() != Some(i) {
+//                         panic!();
+//                     }
+//                 }
+//             }
+//         }
+//     }
+
+//     #[test]
+//     fn test_nonblock_recv_race() {
+//         const N: usize = 1000;
+
+//         for _ in 0..N {
+//             let c = make::<i32>(1);
+//             c.send(1);
+
+//             let t = go!(c, {
+//                 select! {
+//                     recv(c.rx()) -> _ => {}
+//                     default => panic!("chan is not ready"),
+//                 }
+//             });
+
+//             c.close();
+//             c.recv();
+//             t.join().unwrap();
+//         }
+//     }
+
+//     #[test]
+//     fn test_nonblock_select_race() {
+//         const N: usize = 1000;
+
+//         let done = make::<bool>(1);
+//         for _ in 0..N {
+//             let c1 = make::<i32>(1);
+//             let c2 = make::<i32>(1);
+//             c1.send(1);
+
+//             go!(c1, c2, done, {
+//                 select! {
+//                     recv(c1.rx()) -> _ => {}
+//                     recv(c2.rx()) -> _ => {}
+//                     default => {
+//                         done.send(false);
+//                         return;
+//                     }
+//                 }
+//                 done.send(true);
+//             });
+
+//             c2.send(1);
+//             select! {
+//                 recv(c1.rx()) -> _ => {}
+//                 default => {}
+//             }
+//             if !done.recv().unwrap() {
+//                 panic!("no chan is ready");
+//             }
+//         }
+//     }
+
+//     #[test]
+//     fn test_nonblock_select_race2() {
+//         const N: usize = 1000;
+
+//         let done = make::<bool>(1);
+//         for _ in 0..N {
+//             let c1 = make::<i32>(1);
+//             let c2 = make::<i32>(0);
+//             c1.send(1);
+
+//             go!(c1, c2, done, {
+//                 select! {
+//                     recv(c1.rx()) -> _ => {}
+//                     recv(c2.rx()) -> _ => {}
+//                     default => {
+//                         done.send(false);
+//                         return;
+//                     }
+//                 }
+//                 done.send(true);
+//             });
+
+//             c2.close();
+//             select! {
+//                 recv(c1.rx()) -> _ => {}
+//                 default => {}
+//             }
+//             if !done.recv().unwrap() {
+//                 panic!("no chan is ready");
+//             }
+//         }
+//     }
+
+//     #[test]
+//     fn test_self_select() {
+//         // Ensure that send/recv on the same chan in select
+//         // does not crash nor deadlock.
+
+//         for &cap in &[0, 10] {
+//             let wg = WaitGroup::new();
+//             wg.add(2);
+//             let c = make::<i32>(cap);
+
+//             for p in 0..2 {
+//                 let p = p;
+//                 go!(wg, p, c, {
+//                     defer! { wg.done() }
+//                     for i in 0..1000 {
+//                         if p == 0 || i % 2 == 0 {
+//                             select! {
+//                                 send(c.tx(), p) -> _ => {}
+//                                 recv(c.rx()) -> v => {
+//                                     if cap == 0 && v.ok() == Some(p) {
+//                                         panic!("self receive");
+//                                     }
+//                                 }
+//                             }
+//                         } else {
+//                             select! {
+//                                 recv(c.rx()) -> v => {
+//                                     if cap == 0 && v.ok() == Some(p) {
+//                                         panic!("self receive");
+//                                     }
+//                                 }
+//                                 send(c.tx(), p) -> _ => {}
+//                             }
+//                         }
+//                     }
+//                 });
+//             }
+//             wg.wait();
+//         }
+//     }
+
+//     #[test]
+//     fn test_select_stress() {
+//         let c = vec![
+//             make::<i32>(0),
+//             make::<i32>(0),
+//             make::<i32>(2),
+//             make::<i32>(3),
+//         ];
+
+//         const N: usize = 10000;
+
+//         // There are 4 goroutines that send N values on each of the chans,
+//         // + 4 goroutines that receive N values on each of the chans,
+//         // + 1 goroutine that sends N values on each of the chans in a single select,
+//         // + 1 goroutine that receives N values on each of the chans in a single select.
+//         // All these sends, receives and selects interact chaotically at runtime,
+//         // but we are careful that this whole construct does not deadlock.
+//         let wg = WaitGroup::new();
+//         wg.add(10);
+
+//         for k in 0..4 {
+//             go!(k, c, wg, {
+//                 for _ in 0..N {
+//                     c[k].send(0);
+//                 }
+//                 wg.done();
+//             });
+//             go!(k, c, wg, {
+//                 for _ in 0..N {
+//                     c[k].recv();
+//                 }
+//                 wg.done();
+//             });
+//         }
+
+//         go!(c, wg, {
+//             let mut n = [0; 4];
+//             let mut c1 = c.iter().map(|c| Some(c.rx().clone())).collect::<Vec<_>>();
+
+//             for _ in 0..4 * N {
+//                 let index = {
+//                     let mut sel = Select::new();
+//                     let mut opers = [!0; 4];
+//                     for &i in &[3, 2, 0, 1] {
+//                         if let Some(c) = &c1[i] {
+//                             opers[i] = sel.recv(c);
+//                         }
+//                     }
+
+//                     let oper = sel.select();
+//                     let mut index = !0;
+//                     for i in 0..4 {
+//                         if opers[i] == oper.index() {
+//                             index = i;
+//                             let _ = oper.recv(c1[i].as_ref().unwrap());
+//                             break;
+//                         }
+//                     }
+//                     index
+//                 };
+
+//                 n[index] += 1;
+//                 if n[index] == N {
+//                     c1[index] = None;
+//                 }
+//             }
+//             wg.done();
+//         });
+
+//         go!(c, wg, {
+//             let mut n = [0; 4];
+//             let mut c1 = c.iter().map(|c| Some(c.tx().clone())).collect::<Vec<_>>();
+
+//             for _ in 0..4 * N {
+//                 let index = {
+//                     let mut sel = Select::new();
+//                     let mut opers = [!0; 4];
+//                     for &i in &[0, 1, 2, 3] {
+//                         if let Some(c) = &c1[i] {
+//                             opers[i] = sel.send(c);
+//                         }
+//                     }
+
+//                     let oper = sel.select();
+//                     let mut index = !0;
+//                     for i in 0..4 {
+//                         if opers[i] == oper.index() {
+//                             index = i;
+//                             let _ = oper.send(c1[i].as_ref().unwrap(), 0);
+//                             break;
+//                         }
+//                     }
+//                     index
+//                 };
+
+//                 n[index] += 1;
+//                 if n[index] == N {
+//                     c1[index] = None;
+//                 }
+//             }
+//             wg.done();
+//         });
+
+//         wg.wait();
+//     }
+
+//     #[test]
+//     fn test_select_fairness() {
+//         const TRIALS: usize = 10000;
+
+//         let c1 = make::<u8>(TRIALS + 1);
+//         let c2 = make::<u8>(TRIALS + 1);
+
+//         for _ in 0..TRIALS + 1 {
+//             c1.send(1);
+//             c2.send(2);
+//         }
+
+//         let c3 = make::<u8>(0);
+//         let c4 = make::<u8>(0);
+//         let out = make::<u8>(0);
+//         let done = make::<u8>(0);
+//         let wg = WaitGroup::new();
+
+//         wg.add(1);
+//         go!(wg, c1, c2, c3, c4, out, done, {
+//             defer! { wg.done() };
+//             loop {
+//                 let b;
+//                 select! {
+//                     recv(c3.rx()) -> m => b = m.unwrap(),
+//                     recv(c4.rx()) -> m => b = m.unwrap(),
+//                     recv(c1.rx()) -> m => b = m.unwrap(),
+//                     recv(c2.rx()) -> m => b = m.unwrap(),
+//                 }
+//                 select! {
+//                     send(out.tx(), b) -> _ => {}
+//                     recv(done.rx()) -> _ => return,
+//                 }
+//             }
+//         });
+
+//         let (mut cnt1, mut cnt2) = (0, 0);
+//         for _ in 0..TRIALS {
+//             match out.recv() {
+//                 Some(1) => cnt1 += 1,
+//                 Some(2) => cnt2 += 1,
+//                 b => panic!("unexpected value {:?} on channel", b),
+//             }
+//         }
+
+//         // If the select in the goroutine is fair,
+//         // cnt1 and cnt2 should be about the same value.
+//         // With 10,000 trials, the expected margin of error at
+//         // a confidence level of five nines is 4.4172 / (2 * Sqrt(10000)).
+
+//         let r = cnt1 as f64 / TRIALS as f64;
+//         let e = (r - 0.5).abs();
+
+//         if e > 4.4172 / (2.0 * (TRIALS as f64).sqrt()) {
+//             panic!(
+//                 "unfair select: in {} trials, results were {}, {}",
+//                 TRIALS, cnt1, cnt2,
+//             );
+//         }
+
+//         done.close();
+//         wg.wait();
+//     }
+
+//     #[test]
+//     fn test_chan_send_interface() {
+//         struct Mt;
+
+//         let c = make::<Box<dyn Any>>(1);
+//         c.send(Box::new(Mt));
+
+//         select! {
+//             send(c.tx(), Box::new(Mt)) -> _ => {}
+//             default => {}
+//         }
+
+//         select! {
+//             send(c.tx(), Box::new(Mt)) -> _ => {}
+//             send(c.tx(), Box::new(Mt)) -> _ => {}
+//             default => {}
+//         }
+//     }
+
+//     #[test]
+//     fn test_pseudo_random_send() {
+//         const N: usize = 100;
+
+//         for cap in 0..N {
+//             let c = make::<i32>(cap);
+//             let l = Arc::new(Mutex::new(vec![0i32; N]));
+//             let done = make::<bool>(0);
+
+//             go!(c, done, l, {
+//                 let mut l = l.lock().unwrap();
+//                 for i in 0..N {
+//                     thread::yield_now();
+//                     l[i] = c.recv().unwrap();
+//                 }
+//                 done.send(true);
+//             });
+
+//             for _ in 0..N {
+//                 select! {
+//                     send(c.tx(), 1) -> _ => {}
+//                     send(c.tx(), 0) -> _ => {}
+//                 }
+//             }
+//             done.recv();
+
+//             let mut n0 = 0;
+//             let mut n1 = 0;
+//             for &i in l.lock().unwrap().iter() {
+//                 n0 += (i + 1) % 2;
+//                 n1 += i;
+//             }
+
+//             if n0 <= N as i32 / 10 || n1 <= N as i32 / 10 {
+//                 panic!(
+//                     "Want pseudorandom, got {} zeros and {} ones (chan cap {})",
+//                     n0, n1, cap,
+//                 );
+//             }
+//         }
+//     }
+
+//     #[test]
+//     fn test_multi_consumer() {
+//         const NWORK: usize = 23;
+//         const NITER: usize = 271828;
+
+//         let pn = [2, 3, 7, 11, 13, 17, 19, 23, 27, 31];
+
+//         let q = make::<i32>(NWORK * 3);
+//         let r = make::<i32>(NWORK * 3);
+
+//         let wg = WaitGroup::new();
+//         for i in 0..NWORK {
+//             wg.add(1);
+//             let w = i;
+//             go!(q, r, wg, pn, {
+//                 for v in &q {
+//                     if pn[w % pn.len()] == v {
+//                         thread::yield_now();
+//                     }
+//                     r.send(v);
+//                 }
+//                 wg.done();
+//             });
+//         }
+
+//         let expect = Arc::new(Mutex::new(0));
+//         go!(q, r, expect, wg, pn, {
+//             for i in 0..NITER {
+//                 let v = pn[i % pn.len()];
+//                 *expect.lock().unwrap() += v;
+//                 q.send(v);
+//             }
+//             q.close();
+//             wg.wait();
+//             r.close();
+//         });
+
+//         let mut n = 0;
+//         let mut s = 0;
+//         for v in &r {
+//             n += 1;
+//             s += v;
+//         }
+
+//         if n != NITER || s != *expect.lock().unwrap() {
+//             panic!();
+//         }
+//     }
+
+//     #[test]
+//     fn test_select_duplicate_channel() {
+//         // This test makes sure we can queue a G on
+//         // the same channel multiple times.
+//         let c = make::<i32>(0);
+//         let d = make::<i32>(0);
+//         let e = make::<i32>(0);
+
+//         go!(c, d, e, {
+//             select! {
+//                 recv(c.rx()) -> _ => {}
+//                 recv(d.rx()) -> _ => {}
+//                 recv(e.rx()) -> _ => {}
+//             }
+//             e.send(9);
+//         });
+//         thread::sleep(ms(1));
+
+//         go!(c, c.recv());
+//         thread::sleep(ms(1));
+
+//         d.send(7);
+//         e.recv();
+//         c.send(8);
+//     }
+// }
+
+// // https://github.com/golang/go/blob/master/test/closedchan.go
+// mod closedchan {
+//     // TODO
+// }
+
+// // https://github.com/golang/go/blob/master/src/runtime/chanbarrier_test.go
+// mod chanbarrier_test {
+//     // TODO
+// }
+
+// // https://github.com/golang/go/blob/master/src/runtime/race/testdata/chan_test.go
+// mod race_chan_test {
+//     // TODO
+// }
+
+// // https://github.com/golang/go/blob/master/test/ken/chan.go
+// mod chan {
+//     // TODO
+// }
+
+// // https://github.com/golang/go/blob/master/test/ken/chan1.go
+// mod chan1 {
+//     // TODO
+// }
diff --git a/vendor/flume/tests/iter.rs b/vendor/flume/tests/iter.rs
new file mode 100644
index 0000000..4d69adb
--- /dev/null
+++ b/vendor/flume/tests/iter.rs
@@ -0,0 +1,112 @@
+//! Tests for iteration over receivers.
+
+extern crate crossbeam_utils;
+
+use flume::unbounded;
+use crossbeam_utils::thread::scope;
+
+#[test]
+fn nested_recv_iter() {
+    let (s, r) = unbounded::<i32>();
+    let (total_s, total_r) = unbounded::<i32>();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            let mut acc = 0;
+            for x in r.iter() {
+                acc += x;
+            }
+            total_s.send(acc).unwrap();
+        });
+
+        s.send(3).unwrap();
+        s.send(1).unwrap();
+        s.send(2).unwrap();
+        drop(s);
+        assert_eq!(total_r.recv().unwrap(), 6);
+    })
+    .unwrap();
+}
+
+#[test]
+fn recv_iter_break() {
+    let (s, r) = unbounded::<i32>();
+    let (count_s, count_r) = unbounded();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            let mut count = 0;
+            for x in r.iter() {
+                if count >= 3 {
+                    break;
+                } else {
+                    count += x;
+                }
+            }
+            count_s.send(count).unwrap();
+        });
+
+        s.send(2).unwrap();
+        s.send(2).unwrap();
+        s.send(2).unwrap();
+        let _ = s.send(2);
+        drop(s);
+        assert_eq!(count_r.recv().unwrap(), 4);
+    })
+    .unwrap();
+}
+
+#[test]
+fn recv_try_iter() {
+    let (request_s, request_r) = unbounded();
+    let (response_s, response_r) = unbounded();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            let mut count = 0;
+            loop {
+                for x in response_r.try_iter() {
+                    count += x;
+                    if count == 6 {
+                        return;
+                    }
+                }
+                request_s.send(()).unwrap();
+            }
+        });
+
+        for _ in request_r.iter() {
+            if response_s.send(2).is_err() {
+                break;
+            }
+        }
+    })
+    .unwrap();
+}
+
+#[test]
+fn recv_into_iter_owned() {
+    let mut iter = {
+        let (s, r) = unbounded::<i32>();
+        s.send(1).unwrap();
+        s.send(2).unwrap();
+        r.into_iter()
+    };
+
+    assert_eq!(iter.next().unwrap(), 1);
+    assert_eq!(iter.next().unwrap(), 2);
+    assert_eq!(iter.next().is_none(), true);
+}
+
+#[test]
+fn recv_into_iter_borrowed() {
+    let (s, r) = unbounded::<i32>();
+    s.send(1).unwrap();
+    s.send(2).unwrap();
+    drop(s);
+
+    let mut iter = (&r).into_iter();
+    assert_eq!(iter.next().unwrap(), 1);
+    assert_eq!(iter.next().unwrap(), 2);
+    assert_eq!(iter.next().is_none(), true);
+}
diff --git a/vendor/flume/tests/list.rs b/vendor/flume/tests/list.rs
new file mode 100644
index 0000000..851af88
--- /dev/null
+++ b/vendor/flume/tests/list.rs
@@ -0,0 +1,536 @@
+//! Tests for the list channel flavor.
+
+extern crate crossbeam_utils;
+extern crate rand;
+
+use std::any::Any;
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
+use std::thread;
+use std::time::Duration;
+
+use flume::{unbounded, Receiver};
+use flume::{RecvError, RecvTimeoutError, TryRecvError};
+use flume::{SendError, SendTimeoutError, TrySendError};
+use crossbeam_utils::thread::scope;
+use rand::{thread_rng, Rng};
+
+fn ms(ms: u64) -> Duration {
+    Duration::from_millis(ms)
+}
+
+#[test]
+fn smoke() {
+    let (s, r) = unbounded();
+    s.try_send(7).unwrap();
+    assert_eq!(r.try_recv(), Ok(7));
+
+    s.send(8).unwrap();
+    assert_eq!(r.recv(), Ok(8));
+
+    assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+    assert_eq!(r.recv_timeout(ms(1000)), Err(RecvTimeoutError::Timeout));
+}
+
+#[test]
+fn capacity() {
+    let (s, r) = unbounded::<()>();
+    assert_eq!(s.capacity(), None);
+    assert_eq!(r.capacity(), None);
+}
+
+#[test]
+fn len_empty_full() {
+    let (s, r) = unbounded();
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(s.is_empty(), true);
+    assert_eq!(s.is_full(), false);
+    assert_eq!(r.len(), 0);
+    assert_eq!(r.is_empty(), true);
+    assert_eq!(r.is_full(), false);
+
+    s.send(()).unwrap();
+
+    assert_eq!(s.len(), 1);
+    assert_eq!(s.is_empty(), false);
+    assert_eq!(s.is_full(), false);
+    assert_eq!(r.len(), 1);
+    assert_eq!(r.is_empty(), false);
+    assert_eq!(r.is_full(), false);
+
+    r.recv().unwrap();
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(s.is_empty(), true);
+    assert_eq!(s.is_full(), false);
+    assert_eq!(r.len(), 0);
+    assert_eq!(r.is_empty(), true);
+    assert_eq!(r.is_full(), false);
+}
+
+#[test]
+fn try_recv() {
+    let (s, r) = unbounded();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+            thread::sleep(ms(1500));
+            assert_eq!(r.try_recv(), Ok(7));
+            thread::sleep(ms(500));
+            assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected));
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            s.send(7).unwrap();
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn recv() {
+    let (s, r) = unbounded();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(r.recv(), Ok(7));
+            thread::sleep(ms(1000));
+            assert_eq!(r.recv(), Ok(8));
+            thread::sleep(ms(1000));
+            assert_eq!(r.recv(), Ok(9));
+            assert!(r.recv().is_err());
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1500));
+            s.send(7).unwrap();
+            s.send(8).unwrap();
+            s.send(9).unwrap();
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn recv_timeout() {
+    let (s, r) = unbounded::<i32>();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(r.recv_timeout(ms(1000)), Err(RecvTimeoutError::Timeout));
+            assert_eq!(r.recv_timeout(ms(1000)), Ok(7));
+            assert_eq!(
+                r.recv_timeout(ms(1000)),
+                Err(RecvTimeoutError::Disconnected)
+            );
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1500));
+            s.send(7).unwrap();
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn try_send() {
+    let (s, r) = unbounded();
+    for i in 0..1000 {
+        assert_eq!(s.try_send(i), Ok(()));
+    }
+
+    drop(r);
+    assert_eq!(s.try_send(777), Err(TrySendError::Disconnected(777)));
+}
+
+#[test]
+fn send() {
+    let (s, r) = unbounded();
+    for i in 0..1000 {
+        assert_eq!(s.send(i), Ok(()));
+    }
+
+    drop(r);
+    assert_eq!(s.send(777), Err(SendError(777)));
+}
+
+#[test]
+fn send_timeout() {
+    let (s, r) = unbounded();
+    for i in 0..1000 {
+        assert_eq!(s.send_timeout(i, ms(i as u64)), Ok(()));
+    }
+
+    drop(r);
+    assert_eq!(
+        s.send_timeout(777, ms(0)),
+        Err(SendTimeoutError::Disconnected(777))
+    );
+}
+
+#[test]
+fn send_after_disconnect() {
+    let (s, r) = unbounded();
+
+    s.send(1).unwrap();
+    s.send(2).unwrap();
+    s.send(3).unwrap();
+
+    drop(r);
+
+    assert_eq!(s.send(4), Err(SendError(4)));
+    assert_eq!(s.try_send(5), Err(TrySendError::Disconnected(5)));
+    assert_eq!(
+        s.send_timeout(6, ms(0)),
+        Err(SendTimeoutError::Disconnected(6))
+    );
+}
+
+#[test]
+fn recv_after_disconnect() {
+    let (s, r) = unbounded();
+
+    s.send(1).unwrap();
+    s.send(2).unwrap();
+    s.send(3).unwrap();
+
+    drop(s);
+
+    assert_eq!(r.recv(), Ok(1));
+    assert_eq!(r.recv(), Ok(2));
+    assert_eq!(r.recv(), Ok(3));
+    assert!(r.recv().is_err());
+}
+
+#[test]
+fn len() {
+    let (s, r) = unbounded();
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(r.len(), 0);
+
+    for i in 0..50 {
+        s.send(i).unwrap();
+        assert_eq!(s.len(), i + 1);
+    }
+
+    for i in 0..50 {
+        r.recv().unwrap();
+        assert_eq!(r.len(), 50 - i - 1);
+    }
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(r.len(), 0);
+}
+
+#[test]
+fn disconnect_wakes_receiver() {
+    let (s, r) = unbounded::<()>();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert!(r.recv().is_err());
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            drop(s);
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn spsc() {
+    const COUNT: usize = 100_000;
+
+    let (s, r) = unbounded();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            for i in 0..COUNT {
+                assert_eq!(r.recv(), Ok(i));
+            }
+            assert!(r.recv().is_err());
+        });
+        scope.spawn(move |_| {
+            for i in 0..COUNT {
+                s.send(i).unwrap();
+            }
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn mpmc() {
+    const COUNT: usize = 25_000;
+    const THREADS: usize = 4;
+
+    let (s, r) = unbounded::<usize>();
+    let v = (0..COUNT).map(|_| AtomicUsize::new(0)).collect::<Vec<_>>();
+
+    scope(|scope| {
+        for _ in 0..THREADS {
+            scope.spawn(|_| {
+                for _ in 0..COUNT {
+                    let n = r.recv().unwrap();
+                    v[n].fetch_add(1, Ordering::SeqCst);
+                }
+            });
+        }
+        for _ in 0..THREADS {
+            scope.spawn(|_| {
+                for i in 0..COUNT {
+                    s.send(i).unwrap();
+                }
+            });
+        }
+    })
+    .unwrap();
+
+    assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+
+    for c in v {
+        assert_eq!(c.load(Ordering::SeqCst), THREADS);
+    }
+}
+
+#[test]
+fn stress_oneshot() {
+    const COUNT: usize = 10_000;
+
+    for _ in 0..COUNT {
+        let (s, r) = unbounded();
+
+        scope(|scope| {
+            scope.spawn(|_| r.recv().unwrap());
+            scope.spawn(|_| s.send(0).unwrap());
+        })
+        .unwrap();
+    }
+}
+
+#[test]
+fn stress_iter() {
+    const COUNT: usize = 100_000;
+
+    let (request_s, request_r) = unbounded();
+    let (response_s, response_r) = unbounded();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            let mut count = 0;
+            loop {
+                for x in response_r.try_iter() {
+                    count += x;
+                    if count == COUNT {
+                        return;
+                    }
+                }
+                request_s.send(()).unwrap();
+            }
+        });
+
+        for _ in request_r.iter() {
+            if response_s.send(1).is_err() {
+                break;
+            }
+        }
+    })
+    .unwrap();
+}
+
+#[test]
+fn stress_timeout_two_threads() {
+    const COUNT: usize = 100;
+
+    let (s, r) = unbounded();
+
+    scope(|scope| {
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                if i % 2 == 0 {
+                    thread::sleep(ms(50));
+                }
+                s.send(i).unwrap();
+            }
+        });
+
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                if i % 2 == 0 {
+                    thread::sleep(ms(50));
+                }
+                loop {
+                    if let Ok(x) = r.recv_timeout(ms(10)) {
+                        assert_eq!(x, i);
+                        break;
+                    }
+                }
+            }
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn drops() {
+    static DROPS: AtomicUsize = AtomicUsize::new(0);
+
+    #[derive(Debug, PartialEq)]
+    struct DropCounter;
+
+    impl Drop for DropCounter {
+        fn drop(&mut self) {
+            DROPS.fetch_add(1, Ordering::SeqCst);
+        }
+    }
+
+    let mut rng = thread_rng();
+
+    for _ in 0..100 {
+        let steps = rng.gen_range(0..10_000);
+        let additional = rng.gen_range(0..1000);
+
+        DROPS.store(0, Ordering::SeqCst);
+        let (s, r) = unbounded::<DropCounter>();
+
+        scope(|scope| {
+            scope.spawn(|_| {
+                for _ in 0..steps {
+                    r.recv().unwrap();
+                }
+            });
+
+            scope.spawn(|_| {
+                for _ in 0..steps {
+                    s.send(DropCounter).unwrap();
+                }
+            });
+        })
+        .unwrap();
+
+        for _ in 0..additional {
+            s.try_send(DropCounter).unwrap();
+        }
+
+        assert_eq!(DROPS.load(Ordering::SeqCst), steps);
+        drop(s);
+        drop(r);
+        assert_eq!(DROPS.load(Ordering::SeqCst), steps + additional);
+    }
+}
+
+#[test]
+fn linearizable() {
+    const COUNT: usize = 25_000;
+    const THREADS: usize = 4;
+
+    let (s, r) = unbounded();
+
+    scope(|scope| {
+        for _ in 0..THREADS {
+            scope.spawn(|_| {
+                for _ in 0..COUNT {
+                    s.send(0).unwrap();
+                    r.try_recv().unwrap();
+                }
+            });
+        }
+    })
+    .unwrap();
+}
+
+// #[test]
+// fn fairness() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = unbounded::<()>();
+//     let (s2, r2) = unbounded::<()>();
+
+//     for _ in 0..COUNT {
+//         s1.send(()).unwrap();
+//         s2.send(()).unwrap();
+//     }
+
+//     let mut hits = [0usize; 2];
+//     for _ in 0..COUNT {
+//         select! {
+//             recv(r1) -> _ => hits[0] += 1,
+//             recv(r2) -> _ => hits[1] += 1,
+//         }
+//     }
+//     assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+// }
+
+// #[test]
+// fn fairness_duplicates() {
+//     const COUNT: usize = 10_000;
+
+//     let (s, r) = unbounded();
+
+//     for _ in 0..COUNT {
+//         s.send(()).unwrap();
+//     }
+
+//     let mut hits = [0usize; 5];
+//     for _ in 0..COUNT {
+//         select! {
+//             recv(r) -> _ => hits[0] += 1,
+//             recv(r) -> _ => hits[1] += 1,
+//             recv(r) -> _ => hits[2] += 1,
+//             recv(r) -> _ => hits[3] += 1,
+//             recv(r) -> _ => hits[4] += 1,
+//         }
+//     }
+//     assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+// }
+
+// #[test]
+// fn recv_in_send() {
+//     let (s, r) = unbounded();
+//     s.send(()).unwrap();
+
+//     select! {
+//         send(s, assert_eq!(r.recv(), Ok(()))) -> _ => {}
+//     }
+// }
+
+#[test]
+fn channel_through_channel() {
+    const COUNT: usize = 1000;
+
+    type T = Box<dyn Any + Send>;
+
+    let (s, r) = unbounded::<T>();
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            let mut s = s;
+
+            for _ in 0..COUNT {
+                let (new_s, new_r) = unbounded();
+                let new_r: T = Box::new(Some(new_r));
+
+                s.send(new_r).unwrap();
+                s = new_s;
+            }
+        });
+
+        scope.spawn(move |_| {
+            let mut r = r;
+
+            for _ in 0..COUNT {
+                r = r
+                    .recv()
+                    .unwrap()
+                    .downcast_mut::<Option<Receiver<T>>>()
+                    .unwrap()
+                    .take()
+                    .unwrap()
+            }
+        });
+    })
+    .unwrap();
+}
diff --git a/vendor/flume/tests/method_sharing.rs b/vendor/flume/tests/method_sharing.rs
new file mode 100644
index 0000000..24173ea
--- /dev/null
+++ b/vendor/flume/tests/method_sharing.rs
@@ -0,0 +1,39 @@
+#[cfg(feature = "async")]
+use flume::*;
+
+#[cfg(feature = "async")]
+#[async_std::test]
+async fn sender() {
+    let (sender, receiver) = bounded(1);
+
+    let sender_fut = sender.send_async(());
+    assert_eq!(sender.is_disconnected(), sender_fut.is_disconnected());
+    assert_eq!(sender.is_empty(), sender_fut.is_empty());
+    assert_eq!(sender.is_full(), sender_fut.is_full());
+    assert_eq!(sender.len(), sender_fut.len());
+    assert_eq!(sender.capacity(), sender_fut.capacity());
+
+    let sender_sink = sender.sink();
+    assert_eq!(sender.is_disconnected(), sender_sink.is_disconnected());
+    assert_eq!(sender.is_empty(), sender_sink.is_empty());
+    assert_eq!(sender.is_full(), sender_sink.is_full());
+    assert_eq!(sender.len(), sender_sink.len());
+    assert_eq!(sender.capacity(), sender_sink.capacity());
+
+    let receiver_fut = receiver.recv_async();
+    assert_eq!(receiver.is_disconnected(), receiver_fut.is_disconnected());
+    assert_eq!(receiver.is_empty(), receiver_fut.is_empty());
+    assert_eq!(receiver.is_full(), receiver_fut.is_full());
+    assert_eq!(receiver.len(), receiver_fut.len());
+    assert_eq!(receiver.capacity(), receiver_fut.capacity());
+
+    let receiver_stream = receiver.stream();
+    assert_eq!(
+        receiver.is_disconnected(),
+        receiver_stream.is_disconnected()
+    );
+    assert_eq!(receiver.is_empty(), receiver_stream.is_empty());
+    assert_eq!(receiver.is_full(), receiver_stream.is_full());
+    assert_eq!(receiver.len(), receiver_stream.len());
+    assert_eq!(receiver.capacity(), receiver_stream.capacity());
+}
diff --git a/vendor/flume/tests/mpsc.rs b/vendor/flume/tests/mpsc.rs
new file mode 100644
index 0000000..213b9d8
--- /dev/null
+++ b/vendor/flume/tests/mpsc.rs
@@ -0,0 +1,2095 @@
+//! Tests copied from `std::sync::mpsc`.
+//!
+//! This is a copy of tests for the `std::sync::mpsc` channels from the standard library, but
+//! modified to work with `crossbeam-channel` instead.
+//!
+//! Minor tweaks were needed to make the tests compile:
+//!
+//! - Replace `box` syntax with `Box::new`.
+//! - Replace all uses of `Select` with `select!`.
+//! - Change the imports.
+//! - Join all spawned threads.
+//! - Removed assertion from oneshot_multi_thread_send_close_stress tests.
+//!
+//! Source:
+//!   - https://github.com/rust-lang/rust/tree/master/src/libstd/sync/mpsc
+//!
+//! Copyright & License:
+//!   - Copyright 2013-2014 The Rust Project Developers
+//!   - Apache License, Version 2.0 or MIT license, at your option
+//!   - https://github.com/rust-lang/rust/blob/master/COPYRIGHT
+//!   - https://www.rust-lang.org/en-US/legal.html
+
+#[macro_use]
+extern crate crossbeam_channel as cc;
+
+use std::sync::mpsc::{RecvError, RecvTimeoutError, TryRecvError};
+use std::sync::mpsc::{SendError, TrySendError};
+use std::thread::JoinHandle;
+use std::time::Duration;
+
+pub struct Sender<T> {
+    pub inner: cc::Sender<T>,
+}
+
+impl<T> Sender<T> {
+    pub fn send(&self, t: T) -> Result<(), SendError<T>> {
+        self.inner.send(t).map_err(|cc::SendError(m)| SendError(m))
+    }
+}
+
+impl<T> Clone for Sender<T> {
+    fn clone(&self) -> Sender<T> {
+        Sender {
+            inner: self.inner.clone(),
+        }
+    }
+}
+
+pub struct SyncSender<T> {
+    pub inner: cc::Sender<T>,
+}
+
+impl<T> SyncSender<T> {
+    pub fn send(&self, t: T) -> Result<(), SendError<T>> {
+        self.inner.send(t).map_err(|cc::SendError(m)| SendError(m))
+    }
+
+    pub fn try_send(&self, t: T) -> Result<(), TrySendError<T>> {
+        self.inner.try_send(t).map_err(|err| match err {
+            cc::TrySendError::Full(m) => TrySendError::Full(m),
+            cc::TrySendError::Disconnected(m) => TrySendError::Disconnected(m),
+        })
+    }
+}
+
+impl<T> Clone for SyncSender<T> {
+    fn clone(&self) -> SyncSender<T> {
+        SyncSender {
+            inner: self.inner.clone(),
+        }
+    }
+}
+
+pub struct Receiver<T> {
+    pub inner: cc::Receiver<T>,
+}
+
+impl<T> Receiver<T> {
+    pub fn try_recv(&self) -> Result<T, TryRecvError> {
+        self.inner.try_recv().map_err(|err| match err {
+            cc::TryRecvError::Empty => TryRecvError::Empty,
+            cc::TryRecvError::Disconnected => TryRecvError::Disconnected,
+        })
+    }
+
+    pub fn recv(&self) -> Result<T, RecvError> {
+        self.inner.recv().map_err(|_| RecvError)
+    }
+
+    pub fn recv_timeout(&self, timeout: Duration) -> Result<T, RecvTimeoutError> {
+        self.inner.recv_timeout(timeout).map_err(|err| match err {
+            cc::RecvTimeoutError::Timeout => RecvTimeoutError::Timeout,
+            cc::RecvTimeoutError::Disconnected => RecvTimeoutError::Disconnected,
+        })
+    }
+
+    pub fn iter(&self) -> Iter<T> {
+        Iter { inner: self }
+    }
+
+    pub fn try_iter(&self) -> TryIter<T> {
+        TryIter { inner: self }
+    }
+}
+
+impl<'a, T> IntoIterator for &'a Receiver<T> {
+    type Item = T;
+    type IntoIter = Iter<'a, T>;
+
+    fn into_iter(self) -> Iter<'a, T> {
+        self.iter()
+    }
+}
+
+impl<T> IntoIterator for Receiver<T> {
+    type Item = T;
+    type IntoIter = IntoIter<T>;
+
+    fn into_iter(self) -> IntoIter<T> {
+        IntoIter { inner: self }
+    }
+}
+
+pub struct TryIter<'a, T: 'a> {
+    inner: &'a Receiver<T>,
+}
+
+impl<'a, T> Iterator for TryIter<'a, T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<T> {
+        self.inner.try_recv().ok()
+    }
+}
+
+pub struct Iter<'a, T: 'a> {
+    inner: &'a Receiver<T>,
+}
+
+impl<'a, T> Iterator for Iter<'a, T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<T> {
+        self.inner.recv().ok()
+    }
+}
+
+pub struct IntoIter<T> {
+    inner: Receiver<T>,
+}
+
+impl<T> Iterator for IntoIter<T> {
+    type Item = T;
+
+    fn next(&mut self) -> Option<T> {
+        self.inner.recv().ok()
+    }
+}
+
+pub fn channel<T>() -> (Sender<T>, Receiver<T>) {
+    let (s, r) = cc::unbounded();
+    let s = Sender { inner: s };
+    let r = Receiver { inner: r };
+    (s, r)
+}
+
+pub fn sync_channel<T>(bound: usize) -> (SyncSender<T>, Receiver<T>) {
+    let (s, r) = cc::bounded(bound);
+    let s = SyncSender { inner: s };
+    let r = Receiver { inner: r };
+    (s, r)
+}
+
+macro_rules! select {
+    (
+        $($name:pat = $rx:ident.$meth:ident() => $code:expr),+
+    ) => ({
+        crossbeam_channel_internal! {
+            $(
+                recv(($rx).inner) -> res => {
+                    let $name = res.map_err(|_| ::std::sync::mpsc::RecvError);
+                    $code
+                }
+            )+
+        }
+    })
+}
+
+// Source: https://github.com/rust-lang/rust/blob/master/src/libstd/sync/mpsc/mod.rs
+mod channel_tests {
+    use super::*;
+
+    use std::env;
+    use std::thread;
+    use std::time::{Duration, Instant};
+
+    pub fn stress_factor() -> usize {
+        match env::var("RUST_TEST_STRESS") {
+            Ok(val) => val.parse().unwrap(),
+            Err(..) => 1,
+        }
+    }
+
+    #[test]
+    fn smoke() {
+        let (tx, rx) = channel::<i32>();
+        tx.send(1).unwrap();
+        assert_eq!(rx.recv().unwrap(), 1);
+    }
+
+    #[test]
+    fn drop_full() {
+        let (tx, _rx) = channel::<Box<isize>>();
+        tx.send(Box::new(1)).unwrap();
+    }
+
+    #[test]
+    fn drop_full_shared() {
+        let (tx, _rx) = channel::<Box<isize>>();
+        drop(tx.clone());
+        drop(tx.clone());
+        tx.send(Box::new(1)).unwrap();
+    }
+
+    #[test]
+    fn smoke_shared() {
+        let (tx, rx) = channel::<i32>();
+        tx.send(1).unwrap();
+        assert_eq!(rx.recv().unwrap(), 1);
+        let tx = tx.clone();
+        tx.send(1).unwrap();
+        assert_eq!(rx.recv().unwrap(), 1);
+    }
+
+    #[test]
+    fn smoke_threads() {
+        let (tx, rx) = channel::<i32>();
+        let t = thread::spawn(move || {
+            tx.send(1).unwrap();
+        });
+        assert_eq!(rx.recv().unwrap(), 1);
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn smoke_port_gone() {
+        let (tx, rx) = channel::<i32>();
+        drop(rx);
+        assert!(tx.send(1).is_err());
+    }
+
+    #[test]
+    fn smoke_shared_port_gone() {
+        let (tx, rx) = channel::<i32>();
+        drop(rx);
+        assert!(tx.send(1).is_err())
+    }
+
+    #[test]
+    fn smoke_shared_port_gone2() {
+        let (tx, rx) = channel::<i32>();
+        drop(rx);
+        let tx2 = tx.clone();
+        drop(tx);
+        assert!(tx2.send(1).is_err());
+    }
+
+    #[test]
+    fn port_gone_concurrent() {
+        let (tx, rx) = channel::<i32>();
+        let t = thread::spawn(move || {
+            rx.recv().unwrap();
+        });
+        while tx.send(1).is_ok() {}
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn port_gone_concurrent_shared() {
+        let (tx, rx) = channel::<i32>();
+        let tx2 = tx.clone();
+        let t = thread::spawn(move || {
+            rx.recv().unwrap();
+        });
+        while tx.send(1).is_ok() && tx2.send(1).is_ok() {}
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn smoke_chan_gone() {
+        let (tx, rx) = channel::<i32>();
+        drop(tx);
+        assert!(rx.recv().is_err());
+    }
+
+    #[test]
+    fn smoke_chan_gone_shared() {
+        let (tx, rx) = channel::<()>();
+        let tx2 = tx.clone();
+        drop(tx);
+        drop(tx2);
+        assert!(rx.recv().is_err());
+    }
+
+    #[test]
+    fn chan_gone_concurrent() {
+        let (tx, rx) = channel::<i32>();
+        let t = thread::spawn(move || {
+            tx.send(1).unwrap();
+            tx.send(1).unwrap();
+        });
+        while rx.recv().is_ok() {}
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn stress() {
+        let (tx, rx) = channel::<i32>();
+        let t = thread::spawn(move || {
+            for _ in 0..10000 {
+                tx.send(1).unwrap();
+            }
+        });
+        for _ in 0..10000 {
+            assert_eq!(rx.recv().unwrap(), 1);
+        }
+        t.join().ok().unwrap();
+    }
+
+    #[test]
+    fn stress_shared() {
+        const AMT: u32 = 10000;
+        const NTHREADS: u32 = 8;
+        let (tx, rx) = channel::<i32>();
+
+        let t = thread::spawn(move || {
+            for _ in 0..AMT * NTHREADS {
+                assert_eq!(rx.recv().unwrap(), 1);
+            }
+            match rx.try_recv() {
+                Ok(..) => panic!(),
+                _ => {}
+            }
+        });
+
+        let mut ts = Vec::with_capacity(NTHREADS as usize);
+        for _ in 0..NTHREADS {
+            let tx = tx.clone();
+            let t = thread::spawn(move || {
+                for _ in 0..AMT {
+                    tx.send(1).unwrap();
+                }
+            });
+            ts.push(t);
+        }
+        drop(tx);
+        t.join().ok().unwrap();
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn send_from_outside_runtime() {
+        let (tx1, rx1) = channel::<()>();
+        let (tx2, rx2) = channel::<i32>();
+        let t1 = thread::spawn(move || {
+            tx1.send(()).unwrap();
+            for _ in 0..40 {
+                assert_eq!(rx2.recv().unwrap(), 1);
+            }
+        });
+        rx1.recv().unwrap();
+        let t2 = thread::spawn(move || {
+            for _ in 0..40 {
+                tx2.send(1).unwrap();
+            }
+        });
+        t1.join().ok().unwrap();
+        t2.join().ok().unwrap();
+    }
+
+    #[test]
+    fn recv_from_outside_runtime() {
+        let (tx, rx) = channel::<i32>();
+        let t = thread::spawn(move || {
+            for _ in 0..40 {
+                assert_eq!(rx.recv().unwrap(), 1);
+            }
+        });
+        for _ in 0..40 {
+            tx.send(1).unwrap();
+        }
+        t.join().ok().unwrap();
+    }
+
+    #[test]
+    fn no_runtime() {
+        let (tx1, rx1) = channel::<i32>();
+        let (tx2, rx2) = channel::<i32>();
+        let t1 = thread::spawn(move || {
+            assert_eq!(rx1.recv().unwrap(), 1);
+            tx2.send(2).unwrap();
+        });
+        let t2 = thread::spawn(move || {
+            tx1.send(1).unwrap();
+            assert_eq!(rx2.recv().unwrap(), 2);
+        });
+        t1.join().ok().unwrap();
+        t2.join().ok().unwrap();
+    }
+
+    #[test]
+    fn oneshot_single_thread_close_port_first() {
+        // Simple test of closing without sending
+        let (_tx, rx) = channel::<i32>();
+        drop(rx);
+    }
+
+    #[test]
+    fn oneshot_single_thread_close_chan_first() {
+        // Simple test of closing without sending
+        let (tx, _rx) = channel::<i32>();
+        drop(tx);
+    }
+
+    #[test]
+    fn oneshot_single_thread_send_port_close() {
+        // Testing that the sender cleans up the payload if receiver is closed
+        let (tx, rx) = channel::<Box<i32>>();
+        drop(rx);
+        assert!(tx.send(Box::new(0)).is_err());
+    }
+
+    #[test]
+    fn oneshot_single_thread_recv_chan_close() {
+        let (tx, rx) = channel::<i32>();
+        drop(tx);
+        assert_eq!(rx.recv(), Err(RecvError));
+    }
+
+    #[test]
+    fn oneshot_single_thread_send_then_recv() {
+        let (tx, rx) = channel::<Box<i32>>();
+        tx.send(Box::new(10)).unwrap();
+        assert!(*rx.recv().unwrap() == 10);
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_send_open() {
+        let (tx, rx) = channel::<i32>();
+        assert!(tx.send(10).is_ok());
+        assert!(rx.recv().unwrap() == 10);
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_send_closed() {
+        let (tx, rx) = channel::<i32>();
+        drop(rx);
+        assert!(tx.send(10).is_err());
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_recv_open() {
+        let (tx, rx) = channel::<i32>();
+        tx.send(10).unwrap();
+        assert!(rx.recv() == Ok(10));
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_recv_closed() {
+        let (tx, rx) = channel::<i32>();
+        drop(tx);
+        assert!(rx.recv().is_err());
+    }
+
+    #[test]
+    fn oneshot_single_thread_peek_data() {
+        let (tx, rx) = channel::<i32>();
+        assert_eq!(rx.try_recv(), Err(TryRecvError::Empty));
+        tx.send(10).unwrap();
+        assert_eq!(rx.try_recv(), Ok(10));
+    }
+
+    #[test]
+    fn oneshot_single_thread_peek_close() {
+        let (tx, rx) = channel::<i32>();
+        drop(tx);
+        assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected));
+        assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected));
+    }
+
+    #[test]
+    fn oneshot_single_thread_peek_open() {
+        let (_tx, rx) = channel::<i32>();
+        assert_eq!(rx.try_recv(), Err(TryRecvError::Empty));
+    }
+
+    #[test]
+    fn oneshot_multi_task_recv_then_send() {
+        let (tx, rx) = channel::<Box<i32>>();
+        let t = thread::spawn(move || {
+            assert!(*rx.recv().unwrap() == 10);
+        });
+
+        tx.send(Box::new(10)).unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn oneshot_multi_task_recv_then_close() {
+        let (tx, rx) = channel::<Box<i32>>();
+        let t = thread::spawn(move || {
+            drop(tx);
+        });
+        thread::spawn(move || {
+            assert_eq!(rx.recv(), Err(RecvError));
+        })
+        .join()
+        .unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn oneshot_multi_thread_close_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = channel::<i32>();
+            let t = thread::spawn(move || {
+                drop(rx);
+            });
+            ts.push(t);
+            drop(tx);
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn oneshot_multi_thread_send_close_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(2 * stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = channel::<i32>();
+            let t = thread::spawn(move || {
+                drop(rx);
+            });
+            ts.push(t);
+            thread::spawn(move || {
+                let _ = tx.send(1);
+            })
+            .join()
+            .unwrap();
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn oneshot_multi_thread_recv_close_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(2 * stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = channel::<i32>();
+            let t = thread::spawn(move || {
+                thread::spawn(move || {
+                    assert_eq!(rx.recv(), Err(RecvError));
+                })
+                .join()
+                .unwrap();
+            });
+            ts.push(t);
+            let t2 = thread::spawn(move || {
+                let t = thread::spawn(move || {
+                    drop(tx);
+                });
+                t.join().unwrap();
+            });
+            ts.push(t2);
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn oneshot_multi_thread_send_recv_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = channel::<Box<isize>>();
+            let t = thread::spawn(move || {
+                tx.send(Box::new(10)).unwrap();
+            });
+            ts.push(t);
+            assert!(*rx.recv().unwrap() == 10);
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn stream_send_recv_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(2 * stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = channel();
+
+            if let Some(t) = send(tx, 0) {
+                ts.push(t);
+            }
+            if let Some(t2) = recv(rx, 0) {
+                ts.push(t2);
+            }
+
+            fn send(tx: Sender<Box<i32>>, i: i32) -> Option<JoinHandle<()>> {
+                if i == 10 {
+                    return None;
+                }
+
+                Some(thread::spawn(move || {
+                    tx.send(Box::new(i)).unwrap();
+                    send(tx, i + 1);
+                }))
+            }
+
+            fn recv(rx: Receiver<Box<i32>>, i: i32) -> Option<JoinHandle<()>> {
+                if i == 10 {
+                    return None;
+                }
+
+                Some(thread::spawn(move || {
+                    assert!(*rx.recv().unwrap() == i);
+                    recv(rx, i + 1);
+                }))
+            }
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn oneshot_single_thread_recv_timeout() {
+        let (tx, rx) = channel();
+        tx.send(()).unwrap();
+        assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Ok(()));
+        assert_eq!(
+            rx.recv_timeout(Duration::from_millis(1)),
+            Err(RecvTimeoutError::Timeout)
+        );
+        tx.send(()).unwrap();
+        assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Ok(()));
+    }
+
+    #[test]
+    fn stress_recv_timeout_two_threads() {
+        let (tx, rx) = channel();
+        let stress = stress_factor() + 100;
+        let timeout = Duration::from_millis(100);
+
+        let t = thread::spawn(move || {
+            for i in 0..stress {
+                if i % 2 == 0 {
+                    thread::sleep(timeout * 2);
+                }
+                tx.send(1usize).unwrap();
+            }
+        });
+
+        let mut recv_count = 0;
+        loop {
+            match rx.recv_timeout(timeout) {
+                Ok(n) => {
+                    assert_eq!(n, 1usize);
+                    recv_count += 1;
+                }
+                Err(RecvTimeoutError::Timeout) => continue,
+                Err(RecvTimeoutError::Disconnected) => break,
+            }
+        }
+
+        assert_eq!(recv_count, stress);
+        t.join().unwrap()
+    }
+
+    #[test]
+    fn recv_timeout_upgrade() {
+        let (tx, rx) = channel::<()>();
+        let timeout = Duration::from_millis(1);
+        let _tx_clone = tx.clone();
+
+        let start = Instant::now();
+        assert_eq!(rx.recv_timeout(timeout), Err(RecvTimeoutError::Timeout));
+        assert!(Instant::now() >= start + timeout);
+    }
+
+    #[test]
+    fn stress_recv_timeout_shared() {
+        let (tx, rx) = channel();
+        let stress = stress_factor() + 100;
+
+        let mut ts = Vec::with_capacity(stress);
+        for i in 0..stress {
+            let tx = tx.clone();
+            let t = thread::spawn(move || {
+                thread::sleep(Duration::from_millis(i as u64 * 10));
+                tx.send(1usize).unwrap();
+            });
+            ts.push(t);
+        }
+
+        drop(tx);
+
+        let mut recv_count = 0;
+        loop {
+            match rx.recv_timeout(Duration::from_millis(10)) {
+                Ok(n) => {
+                    assert_eq!(n, 1usize);
+                    recv_count += 1;
+                }
+                Err(RecvTimeoutError::Timeout) => continue,
+                Err(RecvTimeoutError::Disconnected) => break,
+            }
+        }
+
+        assert_eq!(recv_count, stress);
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn recv_a_lot() {
+        // Regression test that we don't run out of stack in scheduler context
+        let (tx, rx) = channel();
+        for _ in 0..10000 {
+            tx.send(()).unwrap();
+        }
+        for _ in 0..10000 {
+            rx.recv().unwrap();
+        }
+    }
+
+    #[test]
+    fn shared_recv_timeout() {
+        let (tx, rx) = channel();
+        let total = 5;
+        let mut ts = Vec::with_capacity(total);
+        for _ in 0..total {
+            let tx = tx.clone();
+            let t = thread::spawn(move || {
+                tx.send(()).unwrap();
+            });
+            ts.push(t);
+        }
+
+        for _ in 0..total {
+            rx.recv().unwrap();
+        }
+
+        assert_eq!(
+            rx.recv_timeout(Duration::from_millis(1)),
+            Err(RecvTimeoutError::Timeout)
+        );
+        tx.send(()).unwrap();
+        assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Ok(()));
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn shared_chan_stress() {
+        let (tx, rx) = channel();
+        let total = stress_factor() + 100;
+        let mut ts = Vec::with_capacity(total);
+        for _ in 0..total {
+            let tx = tx.clone();
+            let t = thread::spawn(move || {
+                tx.send(()).unwrap();
+            });
+            ts.push(t);
+        }
+
+        for _ in 0..total {
+            rx.recv().unwrap();
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn test_nested_recv_iter() {
+        let (tx, rx) = channel::<i32>();
+        let (total_tx, total_rx) = channel::<i32>();
+
+        let t = thread::spawn(move || {
+            let mut acc = 0;
+            for x in rx.iter() {
+                acc += x;
+            }
+            total_tx.send(acc).unwrap();
+        });
+
+        tx.send(3).unwrap();
+        tx.send(1).unwrap();
+        tx.send(2).unwrap();
+        drop(tx);
+        assert_eq!(total_rx.recv().unwrap(), 6);
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn test_recv_iter_break() {
+        let (tx, rx) = channel::<i32>();
+        let (count_tx, count_rx) = channel();
+
+        let t = thread::spawn(move || {
+            let mut count = 0;
+            for x in rx.iter() {
+                if count >= 3 {
+                    break;
+                } else {
+                    count += x;
+                }
+            }
+            count_tx.send(count).unwrap();
+        });
+
+        tx.send(2).unwrap();
+        tx.send(2).unwrap();
+        tx.send(2).unwrap();
+        let _ = tx.send(2);
+        drop(tx);
+        assert_eq!(count_rx.recv().unwrap(), 4);
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn test_recv_try_iter() {
+        let (request_tx, request_rx) = channel();
+        let (response_tx, response_rx) = channel();
+
+        // Request `x`s until we have `6`.
+        let t = thread::spawn(move || {
+            let mut count = 0;
+            loop {
+                for x in response_rx.try_iter() {
+                    count += x;
+                    if count == 6 {
+                        return count;
+                    }
+                }
+                request_tx.send(()).unwrap();
+            }
+        });
+
+        for _ in request_rx.iter() {
+            if response_tx.send(2).is_err() {
+                break;
+            }
+        }
+
+        assert_eq!(t.join().unwrap(), 6);
+    }
+
+    #[test]
+    fn test_recv_into_iter_owned() {
+        let mut iter = {
+            let (tx, rx) = channel::<i32>();
+            tx.send(1).unwrap();
+            tx.send(2).unwrap();
+
+            rx.into_iter()
+        };
+        assert_eq!(iter.next().unwrap(), 1);
+        assert_eq!(iter.next().unwrap(), 2);
+        assert_eq!(iter.next().is_none(), true);
+    }
+
+    #[test]
+    fn test_recv_into_iter_borrowed() {
+        let (tx, rx) = channel::<i32>();
+        tx.send(1).unwrap();
+        tx.send(2).unwrap();
+        drop(tx);
+        let mut iter = (&rx).into_iter();
+        assert_eq!(iter.next().unwrap(), 1);
+        assert_eq!(iter.next().unwrap(), 2);
+        assert_eq!(iter.next().is_none(), true);
+    }
+
+    #[test]
+    fn try_recv_states() {
+        let (tx1, rx1) = channel::<i32>();
+        let (tx2, rx2) = channel::<()>();
+        let (tx3, rx3) = channel::<()>();
+        let t = thread::spawn(move || {
+            rx2.recv().unwrap();
+            tx1.send(1).unwrap();
+            tx3.send(()).unwrap();
+            rx2.recv().unwrap();
+            drop(tx1);
+            tx3.send(()).unwrap();
+        });
+
+        assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty));
+        tx2.send(()).unwrap();
+        rx3.recv().unwrap();
+        assert_eq!(rx1.try_recv(), Ok(1));
+        assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty));
+        tx2.send(()).unwrap();
+        rx3.recv().unwrap();
+        assert_eq!(rx1.try_recv(), Err(TryRecvError::Disconnected));
+        t.join().unwrap();
+    }
+
+    // This bug used to end up in a livelock inside of the Receiver destructor
+    // because the internal state of the Shared packet was corrupted
+    #[test]
+    fn destroy_upgraded_shared_port_when_sender_still_active() {
+        let (tx, rx) = channel();
+        let (tx2, rx2) = channel();
+        let t = thread::spawn(move || {
+            rx.recv().unwrap(); // wait on a oneshot
+            drop(rx); // destroy a shared
+            tx2.send(()).unwrap();
+        });
+        // make sure the other thread has gone to sleep
+        for _ in 0..5000 {
+            thread::yield_now();
+        }
+
+        // upgrade to a shared chan and send a message
+        let tx2 = tx.clone();
+        drop(tx);
+        tx2.send(()).unwrap();
+
+        // wait for the child thread to exit before we exit
+        rx2.recv().unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn issue_32114() {
+        let (tx, _) = channel();
+        let _ = tx.send(123);
+        assert_eq!(tx.send(123), Err(SendError(123)));
+    }
+}
+
+// Source: https://github.com/rust-lang/rust/blob/master/src/libstd/sync/mpsc/mod.rs
+mod sync_channel_tests {
+    use super::*;
+
+    use std::env;
+    use std::thread;
+    use std::time::Duration;
+
+    pub fn stress_factor() -> usize {
+        match env::var("RUST_TEST_STRESS") {
+            Ok(val) => val.parse().unwrap(),
+            Err(..) => 1,
+        }
+    }
+
+    #[test]
+    fn smoke() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        tx.send(1).unwrap();
+        assert_eq!(rx.recv().unwrap(), 1);
+    }
+
+    #[test]
+    fn drop_full() {
+        let (tx, _rx) = sync_channel::<Box<isize>>(1);
+        tx.send(Box::new(1)).unwrap();
+    }
+
+    #[test]
+    fn smoke_shared() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        tx.send(1).unwrap();
+        assert_eq!(rx.recv().unwrap(), 1);
+        let tx = tx.clone();
+        tx.send(1).unwrap();
+        assert_eq!(rx.recv().unwrap(), 1);
+    }
+
+    #[test]
+    fn recv_timeout() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        assert_eq!(
+            rx.recv_timeout(Duration::from_millis(1)),
+            Err(RecvTimeoutError::Timeout)
+        );
+        tx.send(1).unwrap();
+        assert_eq!(rx.recv_timeout(Duration::from_millis(1)), Ok(1));
+    }
+
+    #[test]
+    fn smoke_threads() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let t = thread::spawn(move || {
+            tx.send(1).unwrap();
+        });
+        assert_eq!(rx.recv().unwrap(), 1);
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn smoke_port_gone() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        drop(rx);
+        assert!(tx.send(1).is_err());
+    }
+
+    #[test]
+    fn smoke_shared_port_gone2() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        drop(rx);
+        let tx2 = tx.clone();
+        drop(tx);
+        assert!(tx2.send(1).is_err());
+    }
+
+    #[test]
+    fn port_gone_concurrent() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let t = thread::spawn(move || {
+            rx.recv().unwrap();
+        });
+        while tx.send(1).is_ok() {}
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn port_gone_concurrent_shared() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let tx2 = tx.clone();
+        let t = thread::spawn(move || {
+            rx.recv().unwrap();
+        });
+        while tx.send(1).is_ok() && tx2.send(1).is_ok() {}
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn smoke_chan_gone() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        drop(tx);
+        assert!(rx.recv().is_err());
+    }
+
+    #[test]
+    fn smoke_chan_gone_shared() {
+        let (tx, rx) = sync_channel::<()>(0);
+        let tx2 = tx.clone();
+        drop(tx);
+        drop(tx2);
+        assert!(rx.recv().is_err());
+    }
+
+    #[test]
+    fn chan_gone_concurrent() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let t = thread::spawn(move || {
+            tx.send(1).unwrap();
+            tx.send(1).unwrap();
+        });
+        while rx.recv().is_ok() {}
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn stress() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let t = thread::spawn(move || {
+            for _ in 0..10000 {
+                tx.send(1).unwrap();
+            }
+        });
+        for _ in 0..10000 {
+            assert_eq!(rx.recv().unwrap(), 1);
+        }
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn stress_recv_timeout_two_threads() {
+        let (tx, rx) = sync_channel::<i32>(0);
+
+        let t = thread::spawn(move || {
+            for _ in 0..10000 {
+                tx.send(1).unwrap();
+            }
+        });
+
+        let mut recv_count = 0;
+        loop {
+            match rx.recv_timeout(Duration::from_millis(1)) {
+                Ok(v) => {
+                    assert_eq!(v, 1);
+                    recv_count += 1;
+                }
+                Err(RecvTimeoutError::Timeout) => continue,
+                Err(RecvTimeoutError::Disconnected) => break,
+            }
+        }
+
+        assert_eq!(recv_count, 10000);
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn stress_recv_timeout_shared() {
+        const AMT: u32 = 1000;
+        const NTHREADS: u32 = 8;
+        let (tx, rx) = sync_channel::<i32>(0);
+        let (dtx, drx) = sync_channel::<()>(0);
+
+        let t = thread::spawn(move || {
+            let mut recv_count = 0;
+            loop {
+                match rx.recv_timeout(Duration::from_millis(10)) {
+                    Ok(v) => {
+                        assert_eq!(v, 1);
+                        recv_count += 1;
+                    }
+                    Err(RecvTimeoutError::Timeout) => continue,
+                    Err(RecvTimeoutError::Disconnected) => break,
+                }
+            }
+
+            assert_eq!(recv_count, AMT * NTHREADS);
+            assert!(rx.try_recv().is_err());
+
+            dtx.send(()).unwrap();
+        });
+
+        let mut ts = Vec::with_capacity(NTHREADS as usize);
+        for _ in 0..NTHREADS {
+            let tx = tx.clone();
+            let t = thread::spawn(move || {
+                for _ in 0..AMT {
+                    tx.send(1).unwrap();
+                }
+            });
+            ts.push(t);
+        }
+
+        drop(tx);
+
+        drx.recv().unwrap();
+        for t in ts {
+            t.join().unwrap();
+        }
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn stress_shared() {
+        const AMT: u32 = 1000;
+        const NTHREADS: u32 = 8;
+        let (tx, rx) = sync_channel::<i32>(0);
+        let (dtx, drx) = sync_channel::<()>(0);
+
+        let t = thread::spawn(move || {
+            for _ in 0..AMT * NTHREADS {
+                assert_eq!(rx.recv().unwrap(), 1);
+            }
+            match rx.try_recv() {
+                Ok(..) => panic!(),
+                _ => {}
+            }
+            dtx.send(()).unwrap();
+        });
+
+        let mut ts = Vec::with_capacity(NTHREADS as usize);
+        for _ in 0..NTHREADS {
+            let tx = tx.clone();
+            let t = thread::spawn(move || {
+                for _ in 0..AMT {
+                    tx.send(1).unwrap();
+                }
+            });
+            ts.push(t);
+        }
+        drop(tx);
+        drx.recv().unwrap();
+        for t in ts {
+            t.join().unwrap();
+        }
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn oneshot_single_thread_close_port_first() {
+        // Simple test of closing without sending
+        let (_tx, rx) = sync_channel::<i32>(0);
+        drop(rx);
+    }
+
+    #[test]
+    fn oneshot_single_thread_close_chan_first() {
+        // Simple test of closing without sending
+        let (tx, _rx) = sync_channel::<i32>(0);
+        drop(tx);
+    }
+
+    #[test]
+    fn oneshot_single_thread_send_port_close() {
+        // Testing that the sender cleans up the payload if receiver is closed
+        let (tx, rx) = sync_channel::<Box<i32>>(0);
+        drop(rx);
+        assert!(tx.send(Box::new(0)).is_err());
+    }
+
+    #[test]
+    fn oneshot_single_thread_recv_chan_close() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        drop(tx);
+        assert_eq!(rx.recv(), Err(RecvError));
+    }
+
+    #[test]
+    fn oneshot_single_thread_send_then_recv() {
+        let (tx, rx) = sync_channel::<Box<i32>>(1);
+        tx.send(Box::new(10)).unwrap();
+        assert!(*rx.recv().unwrap() == 10);
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_send_open() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        assert_eq!(tx.try_send(10), Ok(()));
+        assert!(rx.recv().unwrap() == 10);
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_send_closed() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        drop(rx);
+        assert_eq!(tx.try_send(10), Err(TrySendError::Disconnected(10)));
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_send_closed2() {
+        let (tx, _rx) = sync_channel::<i32>(0);
+        assert_eq!(tx.try_send(10), Err(TrySendError::Full(10)));
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_recv_open() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        tx.send(10).unwrap();
+        assert!(rx.recv() == Ok(10));
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_recv_closed() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        drop(tx);
+        assert!(rx.recv().is_err());
+    }
+
+    #[test]
+    fn oneshot_single_thread_try_recv_closed_with_data() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        tx.send(10).unwrap();
+        drop(tx);
+        assert_eq!(rx.try_recv(), Ok(10));
+        assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected));
+    }
+
+    #[test]
+    fn oneshot_single_thread_peek_data() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        assert_eq!(rx.try_recv(), Err(TryRecvError::Empty));
+        tx.send(10).unwrap();
+        assert_eq!(rx.try_recv(), Ok(10));
+    }
+
+    #[test]
+    fn oneshot_single_thread_peek_close() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        drop(tx);
+        assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected));
+        assert_eq!(rx.try_recv(), Err(TryRecvError::Disconnected));
+    }
+
+    #[test]
+    fn oneshot_single_thread_peek_open() {
+        let (_tx, rx) = sync_channel::<i32>(0);
+        assert_eq!(rx.try_recv(), Err(TryRecvError::Empty));
+    }
+
+    #[test]
+    fn oneshot_multi_task_recv_then_send() {
+        let (tx, rx) = sync_channel::<Box<i32>>(0);
+        let t = thread::spawn(move || {
+            assert!(*rx.recv().unwrap() == 10);
+        });
+
+        tx.send(Box::new(10)).unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn oneshot_multi_task_recv_then_close() {
+        let (tx, rx) = sync_channel::<Box<i32>>(0);
+        let t = thread::spawn(move || {
+            drop(tx);
+        });
+        thread::spawn(move || {
+            assert_eq!(rx.recv(), Err(RecvError));
+        })
+        .join()
+        .unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn oneshot_multi_thread_close_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = sync_channel::<i32>(0);
+            let t = thread::spawn(move || {
+                drop(rx);
+            });
+            ts.push(t);
+            drop(tx);
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn oneshot_multi_thread_send_close_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = sync_channel::<i32>(0);
+            let t = thread::spawn(move || {
+                drop(rx);
+            });
+            ts.push(t);
+            thread::spawn(move || {
+                let _ = tx.send(1);
+            })
+            .join()
+            .unwrap();
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn oneshot_multi_thread_recv_close_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(2 * stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = sync_channel::<i32>(0);
+            let t = thread::spawn(move || {
+                thread::spawn(move || {
+                    assert_eq!(rx.recv(), Err(RecvError));
+                })
+                .join()
+                .unwrap();
+            });
+            ts.push(t);
+            let t2 = thread::spawn(move || {
+                thread::spawn(move || {
+                    drop(tx);
+                });
+            });
+            ts.push(t2);
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn oneshot_multi_thread_send_recv_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = sync_channel::<Box<i32>>(0);
+            let t = thread::spawn(move || {
+                tx.send(Box::new(10)).unwrap();
+            });
+            ts.push(t);
+            assert!(*rx.recv().unwrap() == 10);
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn stream_send_recv_stress() {
+        let stress_factor = stress_factor();
+        let mut ts = Vec::with_capacity(2 * stress_factor);
+        for _ in 0..stress_factor {
+            let (tx, rx) = sync_channel::<Box<i32>>(0);
+
+            if let Some(t) = send(tx, 0) {
+                ts.push(t);
+            }
+            if let Some(t) = recv(rx, 0) {
+                ts.push(t);
+            }
+
+            fn send(tx: SyncSender<Box<i32>>, i: i32) -> Option<JoinHandle<()>> {
+                if i == 10 {
+                    return None;
+                }
+
+                Some(thread::spawn(move || {
+                    tx.send(Box::new(i)).unwrap();
+                    send(tx, i + 1);
+                }))
+            }
+
+            fn recv(rx: Receiver<Box<i32>>, i: i32) -> Option<JoinHandle<()>> {
+                if i == 10 {
+                    return None;
+                }
+
+                Some(thread::spawn(move || {
+                    assert!(*rx.recv().unwrap() == i);
+                    recv(rx, i + 1);
+                }))
+            }
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn recv_a_lot() {
+        // Regression test that we don't run out of stack in scheduler context
+        let (tx, rx) = sync_channel(10000);
+        for _ in 0..10000 {
+            tx.send(()).unwrap();
+        }
+        for _ in 0..10000 {
+            rx.recv().unwrap();
+        }
+    }
+
+    #[test]
+    fn shared_chan_stress() {
+        let (tx, rx) = sync_channel(0);
+        let total = stress_factor() + 100;
+        let mut ts = Vec::with_capacity(total);
+        for _ in 0..total {
+            let tx = tx.clone();
+            let t = thread::spawn(move || {
+                tx.send(()).unwrap();
+            });
+            ts.push(t);
+        }
+
+        for _ in 0..total {
+            rx.recv().unwrap();
+        }
+        for t in ts {
+            t.join().unwrap();
+        }
+    }
+
+    #[test]
+    fn test_nested_recv_iter() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let (total_tx, total_rx) = sync_channel::<i32>(0);
+
+        let t = thread::spawn(move || {
+            let mut acc = 0;
+            for x in rx.iter() {
+                acc += x;
+            }
+            total_tx.send(acc).unwrap();
+        });
+
+        tx.send(3).unwrap();
+        tx.send(1).unwrap();
+        tx.send(2).unwrap();
+        drop(tx);
+        assert_eq!(total_rx.recv().unwrap(), 6);
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn test_recv_iter_break() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let (count_tx, count_rx) = sync_channel(0);
+
+        let t = thread::spawn(move || {
+            let mut count = 0;
+            for x in rx.iter() {
+                if count >= 3 {
+                    break;
+                } else {
+                    count += x;
+                }
+            }
+            count_tx.send(count).unwrap();
+        });
+
+        tx.send(2).unwrap();
+        tx.send(2).unwrap();
+        tx.send(2).unwrap();
+        let _ = tx.try_send(2);
+        drop(tx);
+        assert_eq!(count_rx.recv().unwrap(), 4);
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn try_recv_states() {
+        let (tx1, rx1) = sync_channel::<i32>(1);
+        let (tx2, rx2) = sync_channel::<()>(1);
+        let (tx3, rx3) = sync_channel::<()>(1);
+        let t = thread::spawn(move || {
+            rx2.recv().unwrap();
+            tx1.send(1).unwrap();
+            tx3.send(()).unwrap();
+            rx2.recv().unwrap();
+            drop(tx1);
+            tx3.send(()).unwrap();
+        });
+
+        assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty));
+        tx2.send(()).unwrap();
+        rx3.recv().unwrap();
+        assert_eq!(rx1.try_recv(), Ok(1));
+        assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty));
+        tx2.send(()).unwrap();
+        rx3.recv().unwrap();
+        assert_eq!(rx1.try_recv(), Err(TryRecvError::Disconnected));
+        t.join().unwrap();
+    }
+
+    // This bug used to end up in a livelock inside of the Receiver destructor
+    // because the internal state of the Shared packet was corrupted
+    #[test]
+    fn destroy_upgraded_shared_port_when_sender_still_active() {
+        let (tx, rx) = sync_channel::<()>(0);
+        let (tx2, rx2) = sync_channel::<()>(0);
+        let t = thread::spawn(move || {
+            rx.recv().unwrap(); // wait on a oneshot
+            drop(rx); // destroy a shared
+            tx2.send(()).unwrap();
+        });
+        // make sure the other thread has gone to sleep
+        for _ in 0..5000 {
+            thread::yield_now();
+        }
+
+        // upgrade to a shared chan and send a message
+        let tx2 = tx.clone();
+        drop(tx);
+        tx2.send(()).unwrap();
+
+        // wait for the child thread to exit before we exit
+        rx2.recv().unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn send1() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let t = thread::spawn(move || {
+            rx.recv().unwrap();
+        });
+        assert_eq!(tx.send(1), Ok(()));
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn send2() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let t = thread::spawn(move || {
+            drop(rx);
+        });
+        assert!(tx.send(1).is_err());
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn send3() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        assert_eq!(tx.send(1), Ok(()));
+        let t = thread::spawn(move || {
+            drop(rx);
+        });
+        assert!(tx.send(1).is_err());
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn send4() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let tx2 = tx.clone();
+        let (done, donerx) = channel();
+        let done2 = done.clone();
+        let t = thread::spawn(move || {
+            assert!(tx.send(1).is_err());
+            done.send(()).unwrap();
+        });
+        let t2 = thread::spawn(move || {
+            assert!(tx2.send(2).is_err());
+            done2.send(()).unwrap();
+        });
+        drop(rx);
+        donerx.recv().unwrap();
+        donerx.recv().unwrap();
+        t.join().unwrap();
+        t2.join().unwrap();
+    }
+
+    #[test]
+    fn try_send1() {
+        let (tx, _rx) = sync_channel::<i32>(0);
+        assert_eq!(tx.try_send(1), Err(TrySendError::Full(1)));
+    }
+
+    #[test]
+    fn try_send2() {
+        let (tx, _rx) = sync_channel::<i32>(1);
+        assert_eq!(tx.try_send(1), Ok(()));
+        assert_eq!(tx.try_send(1), Err(TrySendError::Full(1)));
+    }
+
+    #[test]
+    fn try_send3() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        assert_eq!(tx.try_send(1), Ok(()));
+        drop(rx);
+        assert_eq!(tx.try_send(1), Err(TrySendError::Disconnected(1)));
+    }
+
+    #[test]
+    fn issue_15761() {
+        fn repro() {
+            let (tx1, rx1) = sync_channel::<()>(3);
+            let (tx2, rx2) = sync_channel::<()>(3);
+
+            let _t = thread::spawn(move || {
+                rx1.recv().unwrap();
+                tx2.try_send(()).unwrap();
+            });
+
+            tx1.try_send(()).unwrap();
+            rx2.recv().unwrap();
+        }
+
+        for _ in 0..100 {
+            repro()
+        }
+    }
+}
+
+// Source: https://github.com/rust-lang/rust/blob/master/src/libstd/sync/mpsc/select.rs
+mod select_tests {
+    use super::*;
+
+    use std::thread;
+
+    #[test]
+    fn smoke() {
+        let (tx1, rx1) = channel::<i32>();
+        let (tx2, rx2) = channel::<i32>();
+        tx1.send(1).unwrap();
+        select! {
+            foo = rx1.recv() => { assert_eq!(foo.unwrap(), 1); },
+            _bar = rx2.recv() => { panic!() }
+        }
+        tx2.send(2).unwrap();
+        select! {
+            _foo = rx1.recv() => { panic!() },
+            bar = rx2.recv() => { assert_eq!(bar.unwrap(), 2) }
+        }
+        drop(tx1);
+        select! {
+            foo = rx1.recv() => { assert!(foo.is_err()); },
+            _bar = rx2.recv() => { panic!() }
+        }
+        drop(tx2);
+        select! {
+            bar = rx2.recv() => { assert!(bar.is_err()); }
+        }
+    }
+
+    #[test]
+    fn smoke2() {
+        let (_tx1, rx1) = channel::<i32>();
+        let (_tx2, rx2) = channel::<i32>();
+        let (_tx3, rx3) = channel::<i32>();
+        let (_tx4, rx4) = channel::<i32>();
+        let (tx5, rx5) = channel::<i32>();
+        tx5.send(4).unwrap();
+        select! {
+            _foo = rx1.recv() => { panic!("1") },
+            _foo = rx2.recv() => { panic!("2") },
+            _foo = rx3.recv() => { panic!("3") },
+            _foo = rx4.recv() => { panic!("4") },
+            foo = rx5.recv() => { assert_eq!(foo.unwrap(), 4); }
+        }
+    }
+
+    #[test]
+    fn closed() {
+        let (_tx1, rx1) = channel::<i32>();
+        let (tx2, rx2) = channel::<i32>();
+        drop(tx2);
+
+        select! {
+            _a1 = rx1.recv() => { panic!() },
+            a2 = rx2.recv() => { assert!(a2.is_err()); }
+        }
+    }
+
+    #[test]
+    fn unblocks() {
+        let (tx1, rx1) = channel::<i32>();
+        let (_tx2, rx2) = channel::<i32>();
+        let (tx3, rx3) = channel::<i32>();
+
+        let t = thread::spawn(move || {
+            for _ in 0..20 {
+                thread::yield_now();
+            }
+            tx1.send(1).unwrap();
+            rx3.recv().unwrap();
+            for _ in 0..20 {
+                thread::yield_now();
+            }
+        });
+
+        select! {
+            a = rx1.recv() => { assert_eq!(a.unwrap(), 1); },
+            _b = rx2.recv() => { panic!() }
+        }
+        tx3.send(1).unwrap();
+        select! {
+            a = rx1.recv() => { assert!(a.is_err()) },
+            _b = rx2.recv() => { panic!() }
+        }
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn both_ready() {
+        let (tx1, rx1) = channel::<i32>();
+        let (tx2, rx2) = channel::<i32>();
+        let (tx3, rx3) = channel::<()>();
+
+        let t = thread::spawn(move || {
+            for _ in 0..20 {
+                thread::yield_now();
+            }
+            tx1.send(1).unwrap();
+            tx2.send(2).unwrap();
+            rx3.recv().unwrap();
+        });
+
+        select! {
+            a = rx1.recv() => { assert_eq!(a.unwrap(), 1); },
+            a = rx2.recv() => { assert_eq!(a.unwrap(), 2); }
+        }
+        select! {
+            a = rx1.recv() => { assert_eq!(a.unwrap(), 1); },
+            a = rx2.recv() => { assert_eq!(a.unwrap(), 2); }
+        }
+        assert_eq!(rx1.try_recv(), Err(TryRecvError::Empty));
+        assert_eq!(rx2.try_recv(), Err(TryRecvError::Empty));
+        tx3.send(()).unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn stress() {
+        const AMT: i32 = 10000;
+        let (tx1, rx1) = channel::<i32>();
+        let (tx2, rx2) = channel::<i32>();
+        let (tx3, rx3) = channel::<()>();
+
+        let t = thread::spawn(move || {
+            for i in 0..AMT {
+                if i % 2 == 0 {
+                    tx1.send(i).unwrap();
+                } else {
+                    tx2.send(i).unwrap();
+                }
+                rx3.recv().unwrap();
+            }
+        });
+
+        for i in 0..AMT {
+            select! {
+                i1 = rx1.recv() => { assert!(i % 2 == 0 && i == i1.unwrap()); },
+                i2 = rx2.recv() => { assert!(i % 2 == 1 && i == i2.unwrap()); }
+            }
+            tx3.send(()).unwrap();
+        }
+        t.join().unwrap();
+    }
+
+    #[allow(unused_must_use)]
+    #[test]
+    fn cloning() {
+        let (tx1, rx1) = channel::<i32>();
+        let (_tx2, rx2) = channel::<i32>();
+        let (tx3, rx3) = channel::<()>();
+
+        let t = thread::spawn(move || {
+            rx3.recv().unwrap();
+            tx1.clone();
+            assert_eq!(rx3.try_recv(), Err(TryRecvError::Empty));
+            tx1.send(2).unwrap();
+            rx3.recv().unwrap();
+        });
+
+        tx3.send(()).unwrap();
+        select! {
+            _i1 = rx1.recv() => {},
+            _i2 = rx2.recv() => panic!()
+        }
+        tx3.send(()).unwrap();
+        t.join().unwrap();
+    }
+
+    #[allow(unused_must_use)]
+    #[test]
+    fn cloning2() {
+        let (tx1, rx1) = channel::<i32>();
+        let (_tx2, rx2) = channel::<i32>();
+        let (tx3, rx3) = channel::<()>();
+
+        let t = thread::spawn(move || {
+            rx3.recv().unwrap();
+            tx1.clone();
+            assert_eq!(rx3.try_recv(), Err(TryRecvError::Empty));
+            tx1.send(2).unwrap();
+            rx3.recv().unwrap();
+        });
+
+        tx3.send(()).unwrap();
+        select! {
+            _i1 = rx1.recv() => {},
+            _i2 = rx2.recv() => panic!()
+        }
+        tx3.send(()).unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn cloning3() {
+        let (tx1, rx1) = channel::<()>();
+        let (tx2, rx2) = channel::<()>();
+        let (tx3, rx3) = channel::<()>();
+        let t = thread::spawn(move || {
+            select! {
+                _ = rx1.recv() => panic!(),
+                _ = rx2.recv() => {}
+            }
+            tx3.send(()).unwrap();
+        });
+
+        for _ in 0..1000 {
+            thread::yield_now();
+        }
+        drop(tx1.clone());
+        tx2.send(()).unwrap();
+        rx3.recv().unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn preflight1() {
+        let (tx, rx) = channel();
+        tx.send(()).unwrap();
+        select! {
+            _n = rx.recv() => {}
+        }
+    }
+
+    #[test]
+    fn preflight2() {
+        let (tx, rx) = channel();
+        tx.send(()).unwrap();
+        tx.send(()).unwrap();
+        select! {
+            _n = rx.recv() => {}
+        }
+    }
+
+    #[test]
+    fn preflight3() {
+        let (tx, rx) = channel();
+        drop(tx.clone());
+        tx.send(()).unwrap();
+        select! {
+            _n = rx.recv() => {}
+        }
+    }
+
+    #[test]
+    fn preflight4() {
+        let (tx, rx) = channel();
+        tx.send(()).unwrap();
+        select! {
+            _ = rx.recv() => {}
+        }
+    }
+
+    #[test]
+    fn preflight5() {
+        let (tx, rx) = channel();
+        tx.send(()).unwrap();
+        tx.send(()).unwrap();
+        select! {
+            _ = rx.recv() => {}
+        }
+    }
+
+    #[test]
+    fn preflight6() {
+        let (tx, rx) = channel();
+        drop(tx.clone());
+        tx.send(()).unwrap();
+        select! {
+            _ = rx.recv() => {}
+        }
+    }
+
+    #[test]
+    fn preflight7() {
+        let (tx, rx) = channel::<()>();
+        drop(tx);
+        select! {
+            _ = rx.recv() => {}
+        }
+    }
+
+    #[test]
+    fn preflight8() {
+        let (tx, rx) = channel();
+        tx.send(()).unwrap();
+        drop(tx);
+        rx.recv().unwrap();
+        select! {
+            _ = rx.recv() => {}
+        }
+    }
+
+    #[test]
+    fn preflight9() {
+        let (tx, rx) = channel();
+        drop(tx.clone());
+        tx.send(()).unwrap();
+        drop(tx);
+        rx.recv().unwrap();
+        select! {
+            _ = rx.recv() => {}
+        }
+    }
+
+    #[test]
+    fn oneshot_data_waiting() {
+        let (tx1, rx1) = channel();
+        let (tx2, rx2) = channel();
+        let t = thread::spawn(move || {
+            select! {
+                _n = rx1.recv() => {}
+            }
+            tx2.send(()).unwrap();
+        });
+
+        for _ in 0..100 {
+            thread::yield_now()
+        }
+        tx1.send(()).unwrap();
+        rx2.recv().unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn stream_data_waiting() {
+        let (tx1, rx1) = channel();
+        let (tx2, rx2) = channel();
+        tx1.send(()).unwrap();
+        tx1.send(()).unwrap();
+        rx1.recv().unwrap();
+        rx1.recv().unwrap();
+        let t = thread::spawn(move || {
+            select! {
+                _n = rx1.recv() => {}
+            }
+            tx2.send(()).unwrap();
+        });
+
+        for _ in 0..100 {
+            thread::yield_now()
+        }
+        tx1.send(()).unwrap();
+        rx2.recv().unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn shared_data_waiting() {
+        let (tx1, rx1) = channel();
+        let (tx2, rx2) = channel();
+        drop(tx1.clone());
+        tx1.send(()).unwrap();
+        rx1.recv().unwrap();
+        let t = thread::spawn(move || {
+            select! {
+                _n = rx1.recv() => {}
+            }
+            tx2.send(()).unwrap();
+        });
+
+        for _ in 0..100 {
+            thread::yield_now()
+        }
+        tx1.send(()).unwrap();
+        rx2.recv().unwrap();
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn sync1() {
+        let (tx, rx) = sync_channel::<i32>(1);
+        tx.send(1).unwrap();
+        select! {
+            n = rx.recv() => { assert_eq!(n.unwrap(), 1); }
+        }
+    }
+
+    #[test]
+    fn sync2() {
+        let (tx, rx) = sync_channel::<i32>(0);
+        let t = thread::spawn(move || {
+            for _ in 0..100 {
+                thread::yield_now()
+            }
+            tx.send(1).unwrap();
+        });
+        select! {
+            n = rx.recv() => { assert_eq!(n.unwrap(), 1); }
+        }
+        t.join().unwrap();
+    }
+
+    #[test]
+    fn sync3() {
+        let (tx1, rx1) = sync_channel::<i32>(0);
+        let (tx2, rx2): (Sender<i32>, Receiver<i32>) = channel();
+        let t = thread::spawn(move || {
+            tx1.send(1).unwrap();
+        });
+        let t2 = thread::spawn(move || {
+            tx2.send(2).unwrap();
+        });
+        select! {
+            n = rx1.recv() => {
+                let n = n.unwrap();
+                assert_eq!(n, 1);
+                assert_eq!(rx2.recv().unwrap(), 2);
+            },
+            n = rx2.recv() => {
+                let n = n.unwrap();
+                assert_eq!(n, 2);
+                assert_eq!(rx1.recv().unwrap(), 1);
+            }
+        }
+        t.join().unwrap();
+        t2.join().unwrap();
+    }
+}
diff --git a/vendor/flume/tests/never.rs b/vendor/flume/tests/never.rs
new file mode 100644
index 0000000..676903f
--- /dev/null
+++ b/vendor/flume/tests/never.rs
@@ -0,0 +1,99 @@
+// //! Tests for the never channel flavor.
+
+// #[macro_use]
+// extern crate crossbeam_channel;
+// extern crate rand;
+
+// use std::thread;
+// use std::time::{Duration, Instant};
+
+// use crossbeam_channel::{never, tick, unbounded};
+
+// fn ms(ms: u64) -> Duration {
+//     Duration::from_millis(ms)
+// }
+
+// #[test]
+// fn smoke() {
+//     select! {
+//         recv(never::<i32>()) -> _ => panic!(),
+//         default => {}
+//     }
+// }
+
+// #[test]
+// fn optional() {
+//     let (s, r) = unbounded::<i32>();
+//     s.send(1).unwrap();
+//     s.send(2).unwrap();
+
+//     let mut r = Some(&r);
+//     select! {
+//         recv(r.unwrap_or(&never())) -> _ => {}
+//         default => panic!(),
+//     }
+
+//     r = None;
+//     select! {
+//         recv(r.unwrap_or(&never())) -> _ => panic!(),
+//         default => {}
+//     }
+// }
+
+// #[test]
+// fn tick_n() {
+//     let mut r = tick(ms(100));
+//     let mut step = 0;
+
+//     loop {
+//         select! {
+//             recv(r) -> _ => step += 1,
+//             default(ms(500)) => break,
+//         }
+
+//         if step == 10 {
+//             r = never();
+//         }
+//     }
+
+//     assert_eq!(step, 10);
+// }
+
+// #[test]
+// fn capacity() {
+//     let r = never::<i32>();
+//     assert_eq!(r.capacity(), Some(0));
+// }
+
+// #[test]
+// fn len_empty_full() {
+//     let r = never::<i32>();
+//     assert_eq!(r.len(), 0);
+//     assert_eq!(r.is_empty(), true);
+//     assert_eq!(r.is_full(), true);
+// }
+
+// #[test]
+// fn try_recv() {
+//     let r = never::<i32>();
+//     assert!(r.try_recv().is_err());
+
+//     thread::sleep(ms(100));
+//     assert!(r.try_recv().is_err());
+// }
+
+// #[test]
+// fn recv_timeout() {
+//     let start = Instant::now();
+//     let r = never::<i32>();
+
+//     assert!(r.recv_timeout(ms(100)).is_err());
+//     let now = Instant::now();
+//     assert!(now - start >= ms(100));
+//     assert!(now - start <= ms(150));
+
+//     assert!(r.recv_timeout(ms(100)).is_err());
+//     let now = Instant::now();
+//     assert!(now - start >= ms(200));
+//     assert!(now - start <= ms(250));
+// }
diff --git a/vendor/flume/tests/ready.rs b/vendor/flume/tests/ready.rs
new file mode 100644
index 0000000..2f42d9a
--- /dev/null
+++ b/vendor/flume/tests/ready.rs
@@ -0,0 +1,837 @@
+// //! Tests for channel readiness using the `Select` struct.
+
+// extern crate crossbeam_channel;
+// extern crate crossbeam_utils;
+
+// use std::any::Any;
+// use std::cell::Cell;
+// use std::thread;
+// use std::time::{Duration, Instant};
+
+// use crossbeam_channel::{after, bounded, tick, unbounded};
+// use crossbeam_channel::{Receiver, Select, TryRecvError, TrySendError};
+// use crossbeam_utils::thread::scope;
+
+// fn ms(ms: u64) -> Duration {
+//     Duration::from_millis(ms)
+// }
+
+// #[test]
+// fn smoke1() {
+//     let (s1, r1) = unbounded::<usize>();
+//     let (s2, r2) = unbounded::<usize>();
+
+//     s1.send(1).unwrap();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r1);
+//     sel.recv(&r2);
+//     assert_eq!(sel.ready(), 0);
+//     assert_eq!(r1.try_recv(), Ok(1));
+
+//     s2.send(2).unwrap();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r1);
+//     sel.recv(&r2);
+//     assert_eq!(sel.ready(), 1);
+//     assert_eq!(r2.try_recv(), Ok(2));
+// }
+
+// #[test]
+// fn smoke2() {
+//     let (_s1, r1) = unbounded::<i32>();
+//     let (_s2, r2) = unbounded::<i32>();
+//     let (_s3, r3) = unbounded::<i32>();
+//     let (_s4, r4) = unbounded::<i32>();
+//     let (s5, r5) = unbounded::<i32>();
+
+//     s5.send(5).unwrap();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r1);
+//     sel.recv(&r2);
+//     sel.recv(&r3);
+//     sel.recv(&r4);
+//     sel.recv(&r5);
+//     assert_eq!(sel.ready(), 4);
+//     assert_eq!(r5.try_recv(), Ok(5));
+// }
+
+// #[test]
+// fn disconnected() {
+//     let (s1, r1) = unbounded::<i32>();
+//     let (s2, r2) = unbounded::<i32>();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             drop(s1);
+//             thread::sleep(ms(500));
+//             s2.send(5).unwrap();
+//         });
+
+//         let mut sel = Select::new();
+//         sel.recv(&r1);
+//         sel.recv(&r2);
+//         match sel.ready_timeout(ms(1000)) {
+//             Ok(0) => assert_eq!(r1.try_recv(), Err(TryRecvError::Disconnected)),
+//             _ => panic!(),
+//         }
+
+//         r2.recv().unwrap();
+//     })
+//     .unwrap();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r1);
+//     sel.recv(&r2);
+//     match sel.ready_timeout(ms(1000)) {
+//         Ok(0) => assert_eq!(r1.try_recv(), Err(TryRecvError::Disconnected)),
+//         _ => panic!(),
+//     }
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             drop(s2);
+//         });
+
+//         let mut sel = Select::new();
+//         sel.recv(&r2);
+//         match sel.ready_timeout(ms(1000)) {
+//             Ok(0) => assert_eq!(r2.try_recv(), Err(TryRecvError::Disconnected)),
+//             _ => panic!(),
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn default() {
+//     let (s1, r1) = unbounded::<i32>();
+//     let (s2, r2) = unbounded::<i32>();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r1);
+//     sel.recv(&r2);
+//     assert!(sel.try_ready().is_err());
+
+//     drop(s1);
+
+//     let mut sel = Select::new();
+//     sel.recv(&r1);
+//     sel.recv(&r2);
+//     match sel.try_ready() {
+//         Ok(0) => assert!(r1.try_recv().is_err()),
+//         _ => panic!(),
+//     }
+
+//     s2.send(2).unwrap();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r2);
+//     match sel.try_ready() {
+//         Ok(0) => assert_eq!(r2.try_recv(), Ok(2)),
+//         _ => panic!(),
+//     }
+
+//     let mut sel = Select::new();
+//     sel.recv(&r2);
+//     assert!(sel.try_ready().is_err());
+
+//     let mut sel = Select::new();
+//     assert!(sel.try_ready().is_err());
+// }
+
+// #[test]
+// fn timeout() {
+//     let (_s1, r1) = unbounded::<i32>();
+//     let (s2, r2) = unbounded::<i32>();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(1500));
+//             s2.send(2).unwrap();
+//         });
+
+//         let mut sel = Select::new();
+//         sel.recv(&r1);
+//         sel.recv(&r2);
+//         assert!(sel.ready_timeout(ms(1000)).is_err());
+
+//         let mut sel = Select::new();
+//         sel.recv(&r1);
+//         sel.recv(&r2);
+//         match sel.ready_timeout(ms(1000)) {
+//             Ok(1) => assert_eq!(r2.try_recv(), Ok(2)),
+//             _ => panic!(),
+//         }
+//     })
+//     .unwrap();
+
+//     scope(|scope| {
+//         let (s, r) = unbounded::<i32>();
+
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(500));
+//             drop(s);
+//         });
+
+//         let mut sel = Select::new();
+//         assert!(sel.ready_timeout(ms(1000)).is_err());
+
+//         let mut sel = Select::new();
+//         sel.recv(&r);
+//         match sel.try_ready() {
+//             Ok(0) => assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected)),
+//             _ => panic!(),
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn default_when_disconnected() {
+//     let (_, r) = unbounded::<i32>();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r);
+//     match sel.try_ready() {
+//         Ok(0) => assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected)),
+//         _ => panic!(),
+//     }
+
+//     let (_, r) = unbounded::<i32>();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r);
+//     match sel.ready_timeout(ms(1000)) {
+//         Ok(0) => assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected)),
+//         _ => panic!(),
+//     }
+
+//     let (s, _) = bounded::<i32>(0);
+
+//     let mut sel = Select::new();
+//     sel.send(&s);
+//     match sel.try_ready() {
+//         Ok(0) => assert_eq!(s.try_send(0), Err(TrySendError::Disconnected(0))),
+//         _ => panic!(),
+//     }
+
+//     let (s, _) = bounded::<i32>(0);
+
+//     let mut sel = Select::new();
+//     sel.send(&s);
+//     match sel.ready_timeout(ms(1000)) {
+//         Ok(0) => assert_eq!(s.try_send(0), Err(TrySendError::Disconnected(0))),
+//         _ => panic!(),
+//     }
+// }
+
+// #[test]
+// fn default_only() {
+//     let start = Instant::now();
+
+//     let mut sel = Select::new();
+//     assert!(sel.try_ready().is_err());
+//     let now = Instant::now();
+//     assert!(now - start <= ms(50));
+
+//     let start = Instant::now();
+//     let mut sel = Select::new();
+//     assert!(sel.ready_timeout(ms(500)).is_err());
+//     let now = Instant::now();
+//     assert!(now - start >= ms(450));
+//     assert!(now - start <= ms(550));
+// }
+
+// #[test]
+// fn unblocks() {
+//     let (s1, r1) = bounded::<i32>(0);
+//     let (s2, r2) = bounded::<i32>(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             s2.send(2).unwrap();
+//         });
+
+//         let mut sel = Select::new();
+//         sel.recv(&r1);
+//         sel.recv(&r2);
+//         match sel.ready_timeout(ms(1000)) {
+//             Ok(1) => assert_eq!(r2.try_recv(), Ok(2)),
+//             _ => panic!(),
+//         }
+//     })
+//     .unwrap();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             assert_eq!(r1.recv().unwrap(), 1);
+//         });
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.send(&s1);
+//         let oper2 = sel.send(&s2);
+//         let oper = sel.select_timeout(ms(1000));
+//         match oper {
+//             Err(_) => panic!(),
+//             Ok(oper) => match oper.index() {
+//                 i if i == oper1 => oper.send(&s1, 1).unwrap(),
+//                 i if i == oper2 => panic!(),
+//                 _ => unreachable!(),
+//             },
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn both_ready() {
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             s1.send(1).unwrap();
+//             assert_eq!(r2.recv().unwrap(), 2);
+//         });
+
+//         for _ in 0..2 {
+//             let mut sel = Select::new();
+//             sel.recv(&r1);
+//             sel.send(&s2);
+//             match sel.ready() {
+//                 0 => assert_eq!(r1.try_recv(), Ok(1)),
+//                 1 => s2.try_send(2).unwrap(),
+//                 _ => panic!(),
+//             }
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn cloning1() {
+//     scope(|scope| {
+//         let (s1, r1) = unbounded::<i32>();
+//         let (_s2, r2) = unbounded::<i32>();
+//         let (s3, r3) = unbounded::<()>();
+
+//         scope.spawn(move |_| {
+//             r3.recv().unwrap();
+//             drop(s1.clone());
+//             assert!(r3.try_recv().is_err());
+//             s1.send(1).unwrap();
+//             r3.recv().unwrap();
+//         });
+
+//         s3.send(()).unwrap();
+
+//         let mut sel = Select::new();
+//         sel.recv(&r1);
+//         sel.recv(&r2);
+//         match sel.ready() {
+//             0 => drop(r1.try_recv()),
+//             1 => drop(r2.try_recv()),
+//             _ => panic!(),
+//         }
+
+//         s3.send(()).unwrap();
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn cloning2() {
+//     let (s1, r1) = unbounded::<()>();
+//     let (s2, r2) = unbounded::<()>();
+//     let (_s3, _r3) = unbounded::<()>();
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             let mut sel = Select::new();
+//             sel.recv(&r1);
+//             sel.recv(&r2);
+//             match sel.ready() {
+//                 0 => panic!(),
+//                 1 => drop(r2.try_recv()),
+//                 _ => panic!(),
+//             }
+//         });
+
+//         thread::sleep(ms(500));
+//         drop(s1.clone());
+//         s2.send(()).unwrap();
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn preflight1() {
+//     let (s, r) = unbounded();
+//     s.send(()).unwrap();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r);
+//     match sel.ready() {
+//         0 => drop(r.try_recv()),
+//         _ => panic!(),
+//     }
+// }
+
+// #[test]
+// fn preflight2() {
+//     let (s, r) = unbounded();
+//     drop(s.clone());
+//     s.send(()).unwrap();
+//     drop(s);
+
+//     let mut sel = Select::new();
+//     sel.recv(&r);
+//     match sel.ready() {
+//         0 => assert_eq!(r.try_recv(), Ok(())),
+//         _ => panic!(),
+//     }
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected));
+// }
+
+// #[test]
+// fn preflight3() {
+//     let (s, r) = unbounded();
+//     drop(s.clone());
+//     s.send(()).unwrap();
+//     drop(s);
+//     r.recv().unwrap();
+
+//     let mut sel = Select::new();
+//     sel.recv(&r);
+//     match sel.ready() {
+//         0 => assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected)),
+//         _ => panic!(),
+//     }
+// }
+
+// #[test]
+// fn duplicate_operations() {
+//     let (s, r) = unbounded::<i32>();
+//     let hit = vec![Cell::new(false); 4];
+
+//     while hit.iter().map(|h| h.get()).any(|hit| !hit) {
+//         let mut sel = Select::new();
+//         sel.recv(&r);
+//         sel.recv(&r);
+//         sel.send(&s);
+//         sel.send(&s);
+//         match sel.ready() {
+//             0 => {
+//                 assert!(r.try_recv().is_ok());
+//                 hit[0].set(true);
+//             }
+//             1 => {
+//                 assert!(r.try_recv().is_ok());
+//                 hit[1].set(true);
+//             }
+//             2 => {
+//                 assert!(s.try_send(0).is_ok());
+//                 hit[2].set(true);
+//             }
+//             3 => {
+//                 assert!(s.try_send(0).is_ok());
+//                 hit[3].set(true);
+//             }
+//             _ => panic!(),
+//         }
+//     }
+// }
+
+// #[test]
+// fn nesting() {
+//     let (s, r) = unbounded::<i32>();
+
+//     let mut sel = Select::new();
+//     sel.send(&s);
+//     match sel.ready() {
+//         0 => {
+//             assert!(s.try_send(0).is_ok());
+
+//             let mut sel = Select::new();
+//             sel.recv(&r);
+//             match sel.ready() {
+//                 0 => {
+//                     assert_eq!(r.try_recv(), Ok(0));
+
+//                     let mut sel = Select::new();
+//                     sel.send(&s);
+//                     match sel.ready() {
+//                         0 => {
+//                             assert!(s.try_send(1).is_ok());
+
+//                             let mut sel = Select::new();
+//                             sel.recv(&r);
+//                             match sel.ready() {
+//                                 0 => {
+//                                     assert_eq!(r.try_recv(), Ok(1));
+//                                 }
+//                                 _ => panic!(),
+//                             }
+//                         }
+//                         _ => panic!(),
+//                     }
+//                 }
+//                 _ => panic!(),
+//             }
+//         }
+//         _ => panic!(),
+//     }
+// }
+
+// #[test]
+// fn stress_recv() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = unbounded();
+//     let (s2, r2) = bounded(5);
+//     let (s3, r3) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 s1.send(i).unwrap();
+//                 r3.recv().unwrap();
+
+//                 s2.send(i).unwrap();
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 let mut sel = Select::new();
+//                 sel.recv(&r1);
+//                 sel.recv(&r2);
+//                 match sel.ready() {
+//                     0 => assert_eq!(r1.try_recv(), Ok(i)),
+//                     1 => assert_eq!(r2.try_recv(), Ok(i)),
+//                     _ => panic!(),
+//                 }
+
+//                 s3.send(()).unwrap();
+//             }
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn stress_send() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+//     let (s3, r3) = bounded(100);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 assert_eq!(r1.recv().unwrap(), i);
+//                 assert_eq!(r2.recv().unwrap(), i);
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 let mut sel = Select::new();
+//                 sel.send(&s1);
+//                 sel.send(&s2);
+//                 match sel.ready() {
+//                     0 => assert!(s1.try_send(i).is_ok()),
+//                     1 => assert!(s2.try_send(i).is_ok()),
+//                     _ => panic!(),
+//                 }
+//             }
+//             s3.send(()).unwrap();
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn stress_mixed() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+//     let (s3, r3) = bounded(100);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 s1.send(i).unwrap();
+//                 assert_eq!(r2.recv().unwrap(), i);
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 let mut sel = Select::new();
+//                 sel.recv(&r1);
+//                 sel.send(&s2);
+//                 match sel.ready() {
+//                     0 => assert_eq!(r1.try_recv(), Ok(i)),
+//                     1 => assert!(s2.try_send(i).is_ok()),
+//                     _ => panic!(),
+//                 }
+//             }
+//             s3.send(()).unwrap();
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn stress_timeout_two_threads() {
+//     const COUNT: usize = 20;
+
+//     let (s, r) = bounded(2);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 if i % 2 == 0 {
+//                     thread::sleep(ms(500));
+//                 }
+
+//                 let done = false;
+//                 while !done {
+//                     let mut sel = Select::new();
+//                     sel.send(&s);
+//                     match sel.ready_timeout(ms(100)) {
+//                         Err(_) => {}
+//                         Ok(0) => {
+//                             assert!(s.try_send(i).is_ok());
+//                             break;
+//                         }
+//                         Ok(_) => panic!(),
+//                     }
+//                 }
+//             }
+//         });
+
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 if i % 2 == 0 {
+//                     thread::sleep(ms(500));
+//                 }
+
+//                 let mut done = false;
+//                 while !done {
+//                     let mut sel = Select::new();
+//                     sel.recv(&r);
+//                     match sel.ready_timeout(ms(100)) {
+//                         Err(_) => {}
+//                         Ok(0) => {
+//                             assert_eq!(r.try_recv(), Ok(i));
+//                             done = true;
+//                         }
+//                         Ok(_) => panic!(),
+//                     }
+//                 }
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn send_recv_same_channel() {
+//     let (s, r) = bounded::<i32>(0);
+//     let mut sel = Select::new();
+//     sel.send(&s);
+//     sel.recv(&r);
+//     assert!(sel.ready_timeout(ms(100)).is_err());
+
+//     let (s, r) = unbounded::<i32>();
+//     let mut sel = Select::new();
+//     sel.send(&s);
+//     sel.recv(&r);
+//     match sel.ready_timeout(ms(100)) {
+//         Err(_) => panic!(),
+//         Ok(0) => assert!(s.try_send(0).is_ok()),
+//         Ok(_) => panic!(),
+//     }
+// }
+
+// #[test]
+// fn channel_through_channel() {
+//     const COUNT: usize = 1000;
+
+//     type T = Box<dyn Any + Send>;
+
+//     for cap in 1..4 {
+//         let (s, r) = bounded::<T>(cap);
+
+//         scope(|scope| {
+//             scope.spawn(move |_| {
+//                 let mut s = s;
+
+//                 for _ in 0..COUNT {
+//                     let (new_s, new_r) = bounded(cap);
+//                     let new_r: T = Box::new(Some(new_r));
+
+//                     {
+//                         let mut sel = Select::new();
+//                         sel.send(&s);
+//                         match sel.ready() {
+//                             0 => assert!(s.try_send(new_r).is_ok()),
+//                             _ => panic!(),
+//                         }
+//                     }
+
+//                     s = new_s;
+//                 }
+//             });
+
+//             scope.spawn(move |_| {
+//                 let mut r = r;
+
+//                 for _ in 0..COUNT {
+//                     let new = {
+//                         let mut sel = Select::new();
+//                         sel.recv(&r);
+//                         match sel.ready() {
+//                             0 => r
+//                                 .try_recv()
+//                                 .unwrap()
+//                                 .downcast_mut::<Option<Receiver<T>>>()
+//                                 .unwrap()
+//                                 .take()
+//                                 .unwrap(),
+//                             _ => panic!(),
+//                         }
+//                     };
+//                     r = new;
+//                 }
+//             });
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn fairness1() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded::<()>(COUNT);
+//     let (s2, r2) = unbounded::<()>();
+
+//     for _ in 0..COUNT {
+//         s1.send(()).unwrap();
+//         s2.send(()).unwrap();
+//     }
+
+//     let hits = vec![Cell::new(0usize); 4];
+//     for _ in 0..COUNT {
+//         let after = after(ms(0));
+//         let tick = tick(ms(0));
+
+//         let mut sel = Select::new();
+//         sel.recv(&r1);
+//         sel.recv(&r2);
+//         sel.recv(&after);
+//         sel.recv(&tick);
+//         match sel.ready() {
+//             0 => {
+//                 r1.try_recv().unwrap();
+//                 hits[0].set(hits[0].get() + 1);
+//             }
+//             1 => {
+//                 r2.try_recv().unwrap();
+//                 hits[1].set(hits[1].get() + 1);
+//             }
+//             2 => {
+//                 after.try_recv().unwrap();
+//                 hits[2].set(hits[2].get() + 1);
+//             }
+//             3 => {
+//                 tick.try_recv().unwrap();
+//                 hits[3].set(hits[3].get() + 1);
+//             }
+//             _ => panic!(),
+//         }
+//     }
+//     assert!(hits.iter().all(|x| x.get() >= COUNT / hits.len() / 2));
+// }
+
+// #[test]
+// fn fairness2() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = unbounded::<()>();
+//     let (s2, r2) = bounded::<()>(1);
+//     let (s3, r3) = bounded::<()>(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for _ in 0..COUNT {
+//                 let mut sel = Select::new();
+//                 let mut oper1 = None;
+//                 let mut oper2 = None;
+//                 if s1.is_empty() {
+//                     oper1 = Some(sel.send(&s1));
+//                 }
+//                 if s2.is_empty() {
+//                     oper2 = Some(sel.send(&s2));
+//                 }
+//                 let oper3 = sel.send(&s3);
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     i if Some(i) == oper1 => assert!(oper.send(&s1, ()).is_ok()),
+//                     i if Some(i) == oper2 => assert!(oper.send(&s2, ()).is_ok()),
+//                     i if i == oper3 => assert!(oper.send(&s3, ()).is_ok()),
+//                     _ => unreachable!(),
+//                 }
+//             }
+//         });
+
+//         let hits = vec![Cell::new(0usize); 3];
+//         for _ in 0..COUNT {
+//             let mut sel = Select::new();
+//             sel.recv(&r1);
+//             sel.recv(&r2);
+//             sel.recv(&r3);
+//             loop {
+//                 match sel.ready() {
+//                     0 => {
+//                         if r1.try_recv().is_ok() {
+//                             hits[0].set(hits[0].get() + 1);
+//                             break;
+//                         }
+//                     }
+//                     1 => {
+//                         if r2.try_recv().is_ok() {
+//                             hits[1].set(hits[1].get() + 1);
+//                             break;
+//                         }
+//                     }
+//                     2 => {
+//                         if r3.try_recv().is_ok() {
+//                             hits[2].set(hits[2].get() + 1);
+//                             break;
+//                         }
+//                     }
+//                     _ => unreachable!(),
+//                 }
+//             }
+//         }
+//         assert!(hits.iter().all(|x| x.get() >= COUNT / hits.len() / 10));
+//     })
+//     .unwrap();
+// }
diff --git a/vendor/flume/tests/same_channel.rs b/vendor/flume/tests/same_channel.rs
new file mode 100644
index 0000000..c6452ec
--- /dev/null
+++ b/vendor/flume/tests/same_channel.rs
@@ -0,0 +1,114 @@
+// extern crate crossbeam_channel;
+
+// use std::time::Duration;
+
+// use crossbeam_channel::{after, bounded, never, tick, unbounded};
+
+// fn ms(ms: u64) -> Duration {
+//     Duration::from_millis(ms)
+// }
+
+// #[test]
+// fn after_same_channel() {
+//     let r = after(ms(50));
+
+//     let r2 = r.clone();
+//     assert!(r.same_channel(&r2));
+
+//     let r3 = after(ms(50));
+//     assert!(!r.same_channel(&r3));
+//     assert!(!r2.same_channel(&r3));
+
+//     let r4 = after(ms(100));
+//     assert!(!r.same_channel(&r4));
+//     assert!(!r2.same_channel(&r4));
+// }
+
+// #[test]
+// fn array_same_channel() {
+//     let (s, r) = bounded::<usize>(1);
+
+//     let s2 = s.clone();
+//     assert!(s.same_channel(&s2));
+
+//     let r2 = r.clone();
+//     assert!(r.same_channel(&r2));
+
+//     let (s3, r3) = bounded::<usize>(1);
+//     assert!(!s.same_channel(&s3));
+//     assert!(!s2.same_channel(&s3));
+//     assert!(!r.same_channel(&r3));
+//     assert!(!r2.same_channel(&r3));
+// }
+
+// #[test]
+// fn list_same_channel() {
+//     let (s, r) = unbounded::<usize>();
+
+//     let s2 = s.clone();
+//     assert!(s.same_channel(&s2));
+
+//     let r2 = r.clone();
+//     assert!(r.same_channel(&r2));
+
+//     let (s3, r3) = unbounded::<usize>();
+//     assert!(!s.same_channel(&s3));
+//     assert!(!s2.same_channel(&s3));
+//     assert!(!r.same_channel(&r3));
+//     assert!(!r2.same_channel(&r3));
+// }
+
+// #[test]
+// fn never_same_channel() {
+//     let r = never::<usize>();
+
+//     let r2 = r.clone();
+//     assert!(r.same_channel(&r2));
+
+//     // Never channel are always equal to one another.
+//     let r3 = never::<usize>();
+//     assert!(r.same_channel(&r3));
+//     assert!(r2.same_channel(&r3));
+// }
+
+// #[test]
+// fn tick_same_channel() {
+//     let r = tick(ms(50));
+
+//     let r2 = r.clone();
+//     assert!(r.same_channel(&r2));
+
+//     let r3 = tick(ms(50));
+//     assert!(!r.same_channel(&r3));
+//     assert!(!r2.same_channel(&r3));
+
+//     let r4 = tick(ms(100));
+//     assert!(!r.same_channel(&r4));
+//     assert!(!r2.same_channel(&r4));
+// }
+
+// #[test]
+// fn zero_same_channel() {
+//     let (s, r) = bounded::<usize>(0);
+
+//     let s2 = s.clone();
+//     assert!(s.same_channel(&s2));
+
+//     let r2 = r.clone();
+//     assert!(r.same_channel(&r2));
+
+//     let (s3, r3) = bounded::<usize>(0);
+//     assert!(!s.same_channel(&s3));
+//     assert!(!s2.same_channel(&s3));
+//     assert!(!r.same_channel(&r3));
+//     assert!(!r2.same_channel(&r3));
+// }
+
+// #[test]
+// fn different_flavors_same_channel() {
+//     let (s1, r1) = bounded::<usize>(0);
+//     let (s2, r2) = unbounded::<usize>();
+
+//     assert!(!s1.same_channel(&s2));
+//     assert!(!r1.same_channel(&r2));
+// }
diff --git a/vendor/flume/tests/select.rs b/vendor/flume/tests/select.rs
new file mode 100644
index 0000000..4fac9e9
--- /dev/null
+++ b/vendor/flume/tests/select.rs
@@ -0,0 +1,1304 @@
+// //! Tests for channel selection using the `Select` struct.
+
+// extern crate crossbeam_channel;
+// extern crate crossbeam_utils;
+
+// use std::any::Any;
+// use std::cell::Cell;
+// use std::thread;
+// use std::time::{Duration, Instant};
+
+// use crossbeam_channel::{after, bounded, tick, unbounded, Receiver, Select, TryRecvError};
+// use crossbeam_utils::thread::scope;
+
+// fn ms(ms: u64) -> Duration {
+//     Duration::from_millis(ms)
+// }
+
+// #[test]
+// fn smoke1() {
+//     let (s1, r1) = unbounded::<usize>();
+//     let (s2, r2) = unbounded::<usize>();
+
+//     s1.send(1).unwrap();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r1);
+//     let oper2 = sel.recv(&r2);
+//     let oper = sel.select();
+//     match oper.index() {
+//         i if i == oper1 => assert_eq!(oper.recv(&r1), Ok(1)),
+//         i if i == oper2 => panic!(),
+//         _ => unreachable!(),
+//     }
+
+//     s2.send(2).unwrap();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r1);
+//     let oper2 = sel.recv(&r2);
+//     let oper = sel.select();
+//     match oper.index() {
+//         i if i == oper1 => panic!(),
+//         i if i == oper2 => assert_eq!(oper.recv(&r2), Ok(2)),
+//         _ => unreachable!(),
+//     }
+// }
+
+// #[test]
+// fn smoke2() {
+//     let (_s1, r1) = unbounded::<i32>();
+//     let (_s2, r2) = unbounded::<i32>();
+//     let (_s3, r3) = unbounded::<i32>();
+//     let (_s4, r4) = unbounded::<i32>();
+//     let (s5, r5) = unbounded::<i32>();
+
+//     s5.send(5).unwrap();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r1);
+//     let oper2 = sel.recv(&r2);
+//     let oper3 = sel.recv(&r3);
+//     let oper4 = sel.recv(&r4);
+//     let oper5 = sel.recv(&r5);
+//     let oper = sel.select();
+//     match oper.index() {
+//         i if i == oper1 => panic!(),
+//         i if i == oper2 => panic!(),
+//         i if i == oper3 => panic!(),
+//         i if i == oper4 => panic!(),
+//         i if i == oper5 => assert_eq!(oper.recv(&r5), Ok(5)),
+//         _ => unreachable!(),
+//     }
+// }
+
+// #[test]
+// fn disconnected() {
+//     let (s1, r1) = unbounded::<i32>();
+//     let (s2, r2) = unbounded::<i32>();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             drop(s1);
+//             thread::sleep(ms(500));
+//             s2.send(5).unwrap();
+//         });
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.recv(&r1);
+//         let oper2 = sel.recv(&r2);
+//         let oper = sel.select_timeout(ms(1000));
+//         match oper {
+//             Err(_) => panic!(),
+//             Ok(oper) => match oper.index() {
+//                 i if i == oper1 => assert!(oper.recv(&r1).is_err()),
+//                 i if i == oper2 => panic!(),
+//                 _ => unreachable!(),
+//             },
+//         }
+
+//         r2.recv().unwrap();
+//     })
+//     .unwrap();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r1);
+//     let oper2 = sel.recv(&r2);
+//     let oper = sel.select_timeout(ms(1000));
+//     match oper {
+//         Err(_) => panic!(),
+//         Ok(oper) => match oper.index() {
+//             i if i == oper1 => assert!(oper.recv(&r1).is_err()),
+//             i if i == oper2 => panic!(),
+//             _ => unreachable!(),
+//         },
+//     }
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             drop(s2);
+//         });
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.recv(&r2);
+//         let oper = sel.select_timeout(ms(1000));
+//         match oper {
+//             Err(_) => panic!(),
+//             Ok(oper) => match oper.index() {
+//                 i if i == oper1 => assert!(oper.recv(&r2).is_err()),
+//                 _ => unreachable!(),
+//             },
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn default() {
+//     let (s1, r1) = unbounded::<i32>();
+//     let (s2, r2) = unbounded::<i32>();
+
+//     let mut sel = Select::new();
+//     let _oper1 = sel.recv(&r1);
+//     let _oper2 = sel.recv(&r2);
+//     let oper = sel.try_select();
+//     match oper {
+//         Err(_) => {}
+//         Ok(_) => panic!(),
+//     }
+
+//     drop(s1);
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r1);
+//     let oper2 = sel.recv(&r2);
+//     let oper = sel.try_select();
+//     match oper {
+//         Err(_) => panic!(),
+//         Ok(oper) => match oper.index() {
+//             i if i == oper1 => assert!(oper.recv(&r1).is_err()),
+//             i if i == oper2 => panic!(),
+//             _ => unreachable!(),
+//         },
+//     }
+
+//     s2.send(2).unwrap();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r2);
+//     let oper = sel.try_select();
+//     match oper {
+//         Err(_) => panic!(),
+//         Ok(oper) => match oper.index() {
+//             i if i == oper1 => assert_eq!(oper.recv(&r2), Ok(2)),
+//             _ => unreachable!(),
+//         },
+//     }
+
+//     let mut sel = Select::new();
+//     let _oper1 = sel.recv(&r2);
+//     let oper = sel.try_select();
+//     match oper {
+//         Err(_) => {}
+//         Ok(_) => panic!(),
+//     }
+
+//     let mut sel = Select::new();
+//     let oper = sel.try_select();
+//     match oper {
+//         Err(_) => {}
+//         Ok(_) => panic!(),
+//     }
+// }
+
+// #[test]
+// fn timeout() {
+//     let (_s1, r1) = unbounded::<i32>();
+//     let (s2, r2) = unbounded::<i32>();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(1500));
+//             s2.send(2).unwrap();
+//         });
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.recv(&r1);
+//         let oper2 = sel.recv(&r2);
+//         let oper = sel.select_timeout(ms(1000));
+//         match oper {
+//             Err(_) => {}
+//             Ok(oper) => match oper.index() {
+//                 i if i == oper1 => panic!(),
+//                 i if i == oper2 => panic!(),
+//                 _ => unreachable!(),
+//             },
+//         }
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.recv(&r1);
+//         let oper2 = sel.recv(&r2);
+//         let oper = sel.select_timeout(ms(1000));
+//         match oper {
+//             Err(_) => panic!(),
+//             Ok(oper) => match oper.index() {
+//                 i if i == oper1 => panic!(),
+//                 i if i == oper2 => assert_eq!(oper.recv(&r2), Ok(2)),
+//                 _ => unreachable!(),
+//             },
+//         }
+//     })
+//     .unwrap();
+
+//     scope(|scope| {
+//         let (s, r) = unbounded::<i32>();
+
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(500));
+//             drop(s);
+//         });
+
+//         let mut sel = Select::new();
+//         let oper = sel.select_timeout(ms(1000));
+//         match oper {
+//             Err(_) => {
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.recv(&r);
+//                 let oper = sel.try_select();
+//                 match oper {
+//                     Err(_) => panic!(),
+//                     Ok(oper) => match oper.index() {
+//                         i if i == oper1 => assert!(oper.recv(&r).is_err()),
+//                         _ => unreachable!(),
+//                     },
+//                 }
+//             }
+//             Ok(_) => unreachable!(),
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn default_when_disconnected() {
+//     let (_, r) = unbounded::<i32>();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r);
+//     let oper = sel.try_select();
+//     match oper {
+//         Err(_) => panic!(),
+//         Ok(oper) => match oper.index() {
+//             i if i == oper1 => assert!(oper.recv(&r).is_err()),
+//             _ => unreachable!(),
+//         },
+//     }
+
+//     let (_, r) = unbounded::<i32>();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r);
+//     let oper = sel.select_timeout(ms(1000));
+//     match oper {
+//         Err(_) => panic!(),
+//         Ok(oper) => match oper.index() {
+//             i if i == oper1 => assert!(oper.recv(&r).is_err()),
+//             _ => unreachable!(),
+//         },
+//     }
+
+//     let (s, _) = bounded::<i32>(0);
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.send(&s);
+//     let oper = sel.try_select();
+//     match oper {
+//         Err(_) => panic!(),
+//         Ok(oper) => match oper.index() {
+//             i if i == oper1 => assert!(oper.send(&s, 0).is_err()),
+//             _ => unreachable!(),
+//         },
+//     }
+
+//     let (s, _) = bounded::<i32>(0);
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.send(&s);
+//     let oper = sel.select_timeout(ms(1000));
+//     match oper {
+//         Err(_) => panic!(),
+//         Ok(oper) => match oper.index() {
+//             i if i == oper1 => assert!(oper.send(&s, 0).is_err()),
+//             _ => unreachable!(),
+//         },
+//     }
+// }
+
+// #[test]
+// fn default_only() {
+//     let start = Instant::now();
+
+//     let mut sel = Select::new();
+//     let oper = sel.try_select();
+//     assert!(oper.is_err());
+//     let now = Instant::now();
+//     assert!(now - start <= ms(50));
+
+//     let start = Instant::now();
+//     let mut sel = Select::new();
+//     let oper = sel.select_timeout(ms(500));
+//     assert!(oper.is_err());
+//     let now = Instant::now();
+//     assert!(now - start >= ms(450));
+//     assert!(now - start <= ms(550));
+// }
+
+// #[test]
+// fn unblocks() {
+//     let (s1, r1) = bounded::<i32>(0);
+//     let (s2, r2) = bounded::<i32>(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             s2.send(2).unwrap();
+//         });
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.recv(&r1);
+//         let oper2 = sel.recv(&r2);
+//         let oper = sel.select_timeout(ms(1000));
+//         match oper {
+//             Err(_) => panic!(),
+//             Ok(oper) => match oper.index() {
+//                 i if i == oper1 => panic!(),
+//                 i if i == oper2 => assert_eq!(oper.recv(&r2), Ok(2)),
+//                 _ => unreachable!(),
+//             },
+//         }
+//     })
+//     .unwrap();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             assert_eq!(r1.recv().unwrap(), 1);
+//         });
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.send(&s1);
+//         let oper2 = sel.send(&s2);
+//         let oper = sel.select_timeout(ms(1000));
+//         match oper {
+//             Err(_) => panic!(),
+//             Ok(oper) => match oper.index() {
+//                 i if i == oper1 => oper.send(&s1, 1).unwrap(),
+//                 i if i == oper2 => panic!(),
+//                 _ => unreachable!(),
+//             },
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn both_ready() {
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             s1.send(1).unwrap();
+//             assert_eq!(r2.recv().unwrap(), 2);
+//         });
+
+//         for _ in 0..2 {
+//             let mut sel = Select::new();
+//             let oper1 = sel.recv(&r1);
+//             let oper2 = sel.send(&s2);
+//             let oper = sel.select();
+//             match oper.index() {
+//                 i if i == oper1 => assert_eq!(oper.recv(&r1), Ok(1)),
+//                 i if i == oper2 => oper.send(&s2, 2).unwrap(),
+//                 _ => unreachable!(),
+//             }
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn loop_try() {
+//     const RUNS: usize = 20;
+
+//     for _ in 0..RUNS {
+//         let (s1, r1) = bounded::<i32>(0);
+//         let (s2, r2) = bounded::<i32>(0);
+//         let (s_end, r_end) = bounded::<()>(0);
+
+//         scope(|scope| {
+//             scope.spawn(|_| loop {
+//                 let mut done = false;
+
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.send(&s1);
+//                 let oper = sel.try_select();
+//                 match oper {
+//                     Err(_) => {}
+//                     Ok(oper) => match oper.index() {
+//                         i if i == oper1 => {
+//                             let _ = oper.send(&s1, 1);
+//                             done = true;
+//                         }
+//                         _ => unreachable!(),
+//                     },
+//                 }
+//                 if done {
+//                     break;
+//                 }
+
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.recv(&r_end);
+//                 let oper = sel.try_select();
+//                 match oper {
+//                     Err(_) => {}
+//                     Ok(oper) => match oper.index() {
+//                         i if i == oper1 => {
+//                             let _ = oper.recv(&r_end);
+//                             done = true;
+//                         }
+//                         _ => unreachable!(),
+//                     },
+//                 }
+//                 if done {
+//                     break;
+//                 }
+//             });
+
+//             scope.spawn(|_| loop {
+//                 if let Ok(x) = r2.try_recv() {
+//                     assert_eq!(x, 2);
+//                     break;
+//                 }
+
+//                 let mut done = false;
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.recv(&r_end);
+//                 let oper = sel.try_select();
+//                 match oper {
+//                     Err(_) => {}
+//                     Ok(oper) => match oper.index() {
+//                         i if i == oper1 => {
+//                             let _ = oper.recv(&r_end);
+//                             done = true;
+//                         }
+//                         _ => unreachable!(),
+//                     },
+//                 }
+//                 if done {
+//                     break;
+//                 }
+//             });
+
+//             scope.spawn(|_| {
+//                 thread::sleep(ms(500));
+
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.recv(&r1);
+//                 let oper2 = sel.send(&s2);
+//                 let oper = sel.select_timeout(ms(1000));
+//                 match oper {
+//                     Err(_) => {}
+//                     Ok(oper) => match oper.index() {
+//                         i if i == oper1 => assert_eq!(oper.recv(&r1), Ok(1)),
+//                         i if i == oper2 => assert!(oper.send(&s2, 2).is_ok()),
+//                         _ => unreachable!(),
+//                     },
+//                 }
+
+//                 drop(s_end);
+//             });
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn cloning1() {
+//     scope(|scope| {
+//         let (s1, r1) = unbounded::<i32>();
+//         let (_s2, r2) = unbounded::<i32>();
+//         let (s3, r3) = unbounded::<()>();
+
+//         scope.spawn(move |_| {
+//             r3.recv().unwrap();
+//             drop(s1.clone());
+//             assert!(r3.try_recv().is_err());
+//             s1.send(1).unwrap();
+//             r3.recv().unwrap();
+//         });
+
+//         s3.send(()).unwrap();
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.recv(&r1);
+//         let oper2 = sel.recv(&r2);
+//         let oper = sel.select();
+//         match oper.index() {
+//             i if i == oper1 => drop(oper.recv(&r1)),
+//             i if i == oper2 => drop(oper.recv(&r2)),
+//             _ => unreachable!(),
+//         }
+
+//         s3.send(()).unwrap();
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn cloning2() {
+//     let (s1, r1) = unbounded::<()>();
+//     let (s2, r2) = unbounded::<()>();
+//     let (_s3, _r3) = unbounded::<()>();
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             let mut sel = Select::new();
+//             let oper1 = sel.recv(&r1);
+//             let oper2 = sel.recv(&r2);
+//             let oper = sel.select();
+//             match oper.index() {
+//                 i if i == oper1 => panic!(),
+//                 i if i == oper2 => drop(oper.recv(&r2)),
+//                 _ => unreachable!(),
+//             }
+//         });
+
+//         thread::sleep(ms(500));
+//         drop(s1.clone());
+//         s2.send(()).unwrap();
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn preflight1() {
+//     let (s, r) = unbounded();
+//     s.send(()).unwrap();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r);
+//     let oper = sel.select();
+//     match oper.index() {
+//         i if i == oper1 => drop(oper.recv(&r)),
+//         _ => unreachable!(),
+//     }
+// }
+
+// #[test]
+// fn preflight2() {
+//     let (s, r) = unbounded();
+//     drop(s.clone());
+//     s.send(()).unwrap();
+//     drop(s);
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r);
+//     let oper = sel.select();
+//     match oper.index() {
+//         i if i == oper1 => assert_eq!(oper.recv(&r), Ok(())),
+//         _ => unreachable!(),
+//     }
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected));
+// }
+
+// #[test]
+// fn preflight3() {
+//     let (s, r) = unbounded();
+//     drop(s.clone());
+//     s.send(()).unwrap();
+//     drop(s);
+//     r.recv().unwrap();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r);
+//     let oper = sel.select();
+//     match oper.index() {
+//         i if i == oper1 => assert!(oper.recv(&r).is_err()),
+//         _ => unreachable!(),
+//     }
+// }
+
+// #[test]
+// fn duplicate_operations() {
+//     let (s, r) = unbounded::<i32>();
+//     let hit = vec![Cell::new(false); 4];
+
+//     while hit.iter().map(|h| h.get()).any(|hit| !hit) {
+//         let mut sel = Select::new();
+//         let oper0 = sel.recv(&r);
+//         let oper1 = sel.recv(&r);
+//         let oper2 = sel.send(&s);
+//         let oper3 = sel.send(&s);
+//         let oper = sel.select();
+//         match oper.index() {
+//             i if i == oper0 => {
+//                 assert!(oper.recv(&r).is_ok());
+//                 hit[0].set(true);
+//             }
+//             i if i == oper1 => {
+//                 assert!(oper.recv(&r).is_ok());
+//                 hit[1].set(true);
+//             }
+//             i if i == oper2 => {
+//                 assert!(oper.send(&s, 0).is_ok());
+//                 hit[2].set(true);
+//             }
+//             i if i == oper3 => {
+//                 assert!(oper.send(&s, 0).is_ok());
+//                 hit[3].set(true);
+//             }
+//             _ => unreachable!(),
+//         }
+//     }
+// }
+
+// #[test]
+// fn nesting() {
+//     let (s, r) = unbounded::<i32>();
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.send(&s);
+//     let oper = sel.select();
+//     match oper.index() {
+//         i if i == oper1 => {
+//             assert!(oper.send(&s, 0).is_ok());
+
+//             let mut sel = Select::new();
+//             let oper1 = sel.recv(&r);
+//             let oper = sel.select();
+//             match oper.index() {
+//                 i if i == oper1 => {
+//                     assert_eq!(oper.recv(&r), Ok(0));
+
+//                     let mut sel = Select::new();
+//                     let oper1 = sel.send(&s);
+//                     let oper = sel.select();
+//                     match oper.index() {
+//                         i if i == oper1 => {
+//                             assert!(oper.send(&s, 1).is_ok());
+
+//                             let mut sel = Select::new();
+//                             let oper1 = sel.recv(&r);
+//                             let oper = sel.select();
+//                             match oper.index() {
+//                                 i if i == oper1 => {
+//                                     assert_eq!(oper.recv(&r), Ok(1));
+//                                 }
+//                                 _ => unreachable!(),
+//                             }
+//                         }
+//                         _ => unreachable!(),
+//                     }
+//                 }
+//                 _ => unreachable!(),
+//             }
+//         }
+//         _ => unreachable!(),
+//     }
+// }
+
+// #[test]
+// fn stress_recv() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = unbounded();
+//     let (s2, r2) = bounded(5);
+//     let (s3, r3) = bounded(100);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 s1.send(i).unwrap();
+//                 r3.recv().unwrap();
+
+//                 s2.send(i).unwrap();
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.recv(&r1);
+//                 let oper2 = sel.recv(&r2);
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     ix if ix == oper1 => assert_eq!(oper.recv(&r1), Ok(i)),
+//                     ix if ix == oper2 => assert_eq!(oper.recv(&r2), Ok(i)),
+//                     _ => unreachable!(),
+//                 }
+
+//                 s3.send(()).unwrap();
+//             }
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn stress_send() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+//     let (s3, r3) = bounded(100);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 assert_eq!(r1.recv().unwrap(), i);
+//                 assert_eq!(r2.recv().unwrap(), i);
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.send(&s1);
+//                 let oper2 = sel.send(&s2);
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     ix if ix == oper1 => assert!(oper.send(&s1, i).is_ok()),
+//                     ix if ix == oper2 => assert!(oper.send(&s2, i).is_ok()),
+//                     _ => unreachable!(),
+//                 }
+//             }
+//             s3.send(()).unwrap();
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn stress_mixed() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+//     let (s3, r3) = bounded(100);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 s1.send(i).unwrap();
+//                 assert_eq!(r2.recv().unwrap(), i);
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.recv(&r1);
+//                 let oper2 = sel.send(&s2);
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     ix if ix == oper1 => assert_eq!(oper.recv(&r1), Ok(i)),
+//                     ix if ix == oper2 => assert!(oper.send(&s2, i).is_ok()),
+//                     _ => unreachable!(),
+//                 }
+//             }
+//             s3.send(()).unwrap();
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn stress_timeout_two_threads() {
+//     const COUNT: usize = 20;
+
+//     let (s, r) = bounded(2);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 if i % 2 == 0 {
+//                     thread::sleep(ms(500));
+//                 }
+
+//                 let done = false;
+//                 while !done {
+//                     let mut sel = Select::new();
+//                     let oper1 = sel.send(&s);
+//                     let oper = sel.select_timeout(ms(100));
+//                     match oper {
+//                         Err(_) => {}
+//                         Ok(oper) => match oper.index() {
+//                             ix if ix == oper1 => {
+//                                 assert!(oper.send(&s, i).is_ok());
+//                                 break;
+//                             }
+//                             _ => unreachable!(),
+//                         },
+//                     }
+//                 }
+//             }
+//         });
+
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 if i % 2 == 0 {
+//                     thread::sleep(ms(500));
+//                 }
+
+//                 let mut done = false;
+//                 while !done {
+//                     let mut sel = Select::new();
+//                     let oper1 = sel.recv(&r);
+//                     let oper = sel.select_timeout(ms(100));
+//                     match oper {
+//                         Err(_) => {}
+//                         Ok(oper) => match oper.index() {
+//                             ix if ix == oper1 => {
+//                                 assert_eq!(oper.recv(&r), Ok(i));
+//                                 done = true;
+//                             }
+//                             _ => unreachable!(),
+//                         },
+//                     }
+//                 }
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn send_recv_same_channel() {
+//     let (s, r) = bounded::<i32>(0);
+//     let mut sel = Select::new();
+//     let oper1 = sel.send(&s);
+//     let oper2 = sel.recv(&r);
+//     let oper = sel.select_timeout(ms(100));
+//     match oper {
+//         Err(_) => {}
+//         Ok(oper) => match oper.index() {
+//             ix if ix == oper1 => panic!(),
+//             ix if ix == oper2 => panic!(),
+//             _ => unreachable!(),
+//         },
+//     }
+
+//     let (s, r) = unbounded::<i32>();
+//     let mut sel = Select::new();
+//     let oper1 = sel.send(&s);
+//     let oper2 = sel.recv(&r);
+//     let oper = sel.select_timeout(ms(100));
+//     match oper {
+//         Err(_) => panic!(),
+//         Ok(oper) => match oper.index() {
+//             ix if ix == oper1 => assert!(oper.send(&s, 0).is_ok()),
+//             ix if ix == oper2 => panic!(),
+//             _ => unreachable!(),
+//         },
+//     }
+// }
+
+// #[test]
+// fn matching() {
+//     const THREADS: usize = 44;
+
+//     let (s, r) = &bounded::<usize>(0);
+
+//     scope(|scope| {
+//         for i in 0..THREADS {
+//             scope.spawn(move |_| {
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.recv(&r);
+//                 let oper2 = sel.send(&s);
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     ix if ix == oper1 => assert_ne!(oper.recv(&r), Ok(i)),
+//                     ix if ix == oper2 => assert!(oper.send(&s, i).is_ok()),
+//                     _ => unreachable!(),
+//                 }
+//             });
+//         }
+//     })
+//     .unwrap();
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn matching_with_leftover() {
+//     const THREADS: usize = 55;
+
+//     let (s, r) = &bounded::<usize>(0);
+
+//     scope(|scope| {
+//         for i in 0..THREADS {
+//             scope.spawn(move |_| {
+//                 let mut sel = Select::new();
+//                 let oper1 = sel.recv(&r);
+//                 let oper2 = sel.send(&s);
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     ix if ix == oper1 => assert_ne!(oper.recv(&r), Ok(i)),
+//                     ix if ix == oper2 => assert!(oper.send(&s, i).is_ok()),
+//                     _ => unreachable!(),
+//                 }
+//             });
+//         }
+//         s.send(!0).unwrap();
+//     })
+//     .unwrap();
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn channel_through_channel() {
+//     const COUNT: usize = 1000;
+
+//     type T = Box<dyn Any + Send>;
+
+//     for cap in 0..3 {
+//         let (s, r) = bounded::<T>(cap);
+
+//         scope(|scope| {
+//             scope.spawn(move |_| {
+//                 let mut s = s;
+
+//                 for _ in 0..COUNT {
+//                     let (new_s, new_r) = bounded(cap);
+//                     let new_r: T = Box::new(Some(new_r));
+
+//                     {
+//                         let mut sel = Select::new();
+//                         let oper1 = sel.send(&s);
+//                         let oper = sel.select();
+//                         match oper.index() {
+//                             ix if ix == oper1 => assert!(oper.send(&s, new_r).is_ok()),
+//                             _ => unreachable!(),
+//                         }
+//                     }
+
+//                     s = new_s;
+//                 }
+//             });
+
+//             scope.spawn(move |_| {
+//                 let mut r = r;
+
+//                 for _ in 0..COUNT {
+//                     let new = {
+//                         let mut sel = Select::new();
+//                         let oper1 = sel.recv(&r);
+//                         let oper = sel.select();
+//                         match oper.index() {
+//                             ix if ix == oper1 => oper
+//                                 .recv(&r)
+//                                 .unwrap()
+//                                 .downcast_mut::<Option<Receiver<T>>>()
+//                                 .unwrap()
+//                                 .take()
+//                                 .unwrap(),
+//                             _ => unreachable!(),
+//                         }
+//                     };
+//                     r = new;
+//                 }
+//             });
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn linearizable_try() {
+//     const COUNT: usize = 100_000;
+
+//     for step in 0..2 {
+//         let (start_s, start_r) = bounded::<()>(0);
+//         let (end_s, end_r) = bounded::<()>(0);
+
+//         let ((s1, r1), (s2, r2)) = if step == 0 {
+//             (bounded::<i32>(1), bounded::<i32>(1))
+//         } else {
+//             (unbounded::<i32>(), unbounded::<i32>())
+//         };
+
+//         scope(|scope| {
+//             scope.spawn(|_| {
+//                 for _ in 0..COUNT {
+//                     start_s.send(()).unwrap();
+
+//                     s1.send(1).unwrap();
+
+//                     let mut sel = Select::new();
+//                     let oper1 = sel.recv(&r1);
+//                     let oper2 = sel.recv(&r2);
+//                     let oper = sel.try_select();
+//                     match oper {
+//                         Err(_) => unreachable!(),
+//                         Ok(oper) => match oper.index() {
+//                             ix if ix == oper1 => assert!(oper.recv(&r1).is_ok()),
+//                             ix if ix == oper2 => assert!(oper.recv(&r2).is_ok()),
+//                             _ => unreachable!(),
+//                         },
+//                     }
+
+//                     end_s.send(()).unwrap();
+//                     let _ = r2.try_recv();
+//                 }
+//             });
+
+//             for _ in 0..COUNT {
+//                 start_r.recv().unwrap();
+
+//                 s2.send(1).unwrap();
+//                 let _ = r1.try_recv();
+
+//                 end_r.recv().unwrap();
+//             }
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn linearizable_timeout() {
+//     const COUNT: usize = 100_000;
+
+//     for step in 0..2 {
+//         let (start_s, start_r) = bounded::<()>(0);
+//         let (end_s, end_r) = bounded::<()>(0);
+
+//         let ((s1, r1), (s2, r2)) = if step == 0 {
+//             (bounded::<i32>(1), bounded::<i32>(1))
+//         } else {
+//             (unbounded::<i32>(), unbounded::<i32>())
+//         };
+
+//         scope(|scope| {
+//             scope.spawn(|_| {
+//                 for _ in 0..COUNT {
+//                     start_s.send(()).unwrap();
+
+//                     s1.send(1).unwrap();
+
+//                     let mut sel = Select::new();
+//                     let oper1 = sel.recv(&r1);
+//                     let oper2 = sel.recv(&r2);
+//                     let oper = sel.select_timeout(ms(0));
+//                     match oper {
+//                         Err(_) => unreachable!(),
+//                         Ok(oper) => match oper.index() {
+//                             ix if ix == oper1 => assert!(oper.recv(&r1).is_ok()),
+//                             ix if ix == oper2 => assert!(oper.recv(&r2).is_ok()),
+//                             _ => unreachable!(),
+//                         },
+//                     }
+
+//                     end_s.send(()).unwrap();
+//                     let _ = r2.try_recv();
+//                 }
+//             });
+
+//             for _ in 0..COUNT {
+//                 start_r.recv().unwrap();
+
+//                 s2.send(1).unwrap();
+//                 let _ = r1.try_recv();
+
+//                 end_r.recv().unwrap();
+//             }
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn fairness1() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded::<()>(COUNT);
+//     let (s2, r2) = unbounded::<()>();
+
+//     for _ in 0..COUNT {
+//         s1.send(()).unwrap();
+//         s2.send(()).unwrap();
+//     }
+
+//     let hits = vec![Cell::new(0usize); 4];
+//     for _ in 0..COUNT {
+//         let after = after(ms(0));
+//         let tick = tick(ms(0));
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.recv(&r1);
+//         let oper2 = sel.recv(&r2);
+//         let oper3 = sel.recv(&after);
+//         let oper4 = sel.recv(&tick);
+//         let oper = sel.select();
+//         match oper.index() {
+//             i if i == oper1 => {
+//                 oper.recv(&r1).unwrap();
+//                 hits[0].set(hits[0].get() + 1);
+//             }
+//             i if i == oper2 => {
+//                 oper.recv(&r2).unwrap();
+//                 hits[1].set(hits[1].get() + 1);
+//             }
+//             i if i == oper3 => {
+//                 oper.recv(&after).unwrap();
+//                 hits[2].set(hits[2].get() + 1);
+//             }
+//             i if i == oper4 => {
+//                 oper.recv(&tick).unwrap();
+//                 hits[3].set(hits[3].get() + 1);
+//             }
+//             _ => unreachable!(),
+//         }
+//     }
+//     assert!(hits.iter().all(|x| x.get() >= COUNT / hits.len() / 2));
+// }
+
+// #[test]
+// fn fairness2() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = unbounded::<()>();
+//     let (s2, r2) = bounded::<()>(1);
+//     let (s3, r3) = bounded::<()>(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for _ in 0..COUNT {
+//                 let mut sel = Select::new();
+//                 let mut oper1 = None;
+//                 let mut oper2 = None;
+//                 if s1.is_empty() {
+//                     oper1 = Some(sel.send(&s1));
+//                 }
+//                 if s2.is_empty() {
+//                     oper2 = Some(sel.send(&s2));
+//                 }
+//                 let oper3 = sel.send(&s3);
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     i if Some(i) == oper1 => assert!(oper.send(&s1, ()).is_ok()),
+//                     i if Some(i) == oper2 => assert!(oper.send(&s2, ()).is_ok()),
+//                     i if i == oper3 => assert!(oper.send(&s3, ()).is_ok()),
+//                     _ => unreachable!(),
+//                 }
+//             }
+//         });
+
+//         let hits = vec![Cell::new(0usize); 3];
+//         for _ in 0..COUNT {
+//             let mut sel = Select::new();
+//             let oper1 = sel.recv(&r1);
+//             let oper2 = sel.recv(&r2);
+//             let oper3 = sel.recv(&r3);
+//             let oper = sel.select();
+//             match oper.index() {
+//                 i if i == oper1 => {
+//                     oper.recv(&r1).unwrap();
+//                     hits[0].set(hits[0].get() + 1);
+//                 }
+//                 i if i == oper2 => {
+//                     oper.recv(&r2).unwrap();
+//                     hits[1].set(hits[1].get() + 1);
+//                 }
+//                 i if i == oper3 => {
+//                     oper.recv(&r3).unwrap();
+//                     hits[2].set(hits[2].get() + 1);
+//                 }
+//                 _ => unreachable!(),
+//             }
+//         }
+//         assert!(hits.iter().all(|x| x.get() >= COUNT / hits.len() / 50));
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn sync_and_clone() {
+//     const THREADS: usize = 20;
+
+//     let (s, r) = &bounded::<usize>(0);
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r);
+//     let oper2 = sel.send(&s);
+//     let sel = &sel;
+
+//     scope(|scope| {
+//         for i in 0..THREADS {
+//             scope.spawn(move |_| {
+//                 let mut sel = sel.clone();
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     ix if ix == oper1 => assert_ne!(oper.recv(&r), Ok(i)),
+//                     ix if ix == oper2 => assert!(oper.send(&s, i).is_ok()),
+//                     _ => unreachable!(),
+//                 }
+//             });
+//         }
+//     })
+//     .unwrap();
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn send_and_clone() {
+//     const THREADS: usize = 20;
+
+//     let (s, r) = &bounded::<usize>(0);
+
+//     let mut sel = Select::new();
+//     let oper1 = sel.recv(&r);
+//     let oper2 = sel.send(&s);
+
+//     scope(|scope| {
+//         for i in 0..THREADS {
+//             let mut sel = sel.clone();
+//             scope.spawn(move |_| {
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     ix if ix == oper1 => assert_ne!(oper.recv(&r), Ok(i)),
+//                     ix if ix == oper2 => assert!(oper.send(&s, i).is_ok()),
+//                     _ => unreachable!(),
+//                 }
+//             });
+//         }
+//     })
+//     .unwrap();
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn reuse() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+//     let (s3, r3) = bounded(100);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 s1.send(i).unwrap();
+//                 assert_eq!(r2.recv().unwrap(), i);
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         let mut sel = Select::new();
+//         let oper1 = sel.recv(&r1);
+//         let oper2 = sel.send(&s2);
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 let oper = sel.select();
+//                 match oper.index() {
+//                     ix if ix == oper1 => assert_eq!(oper.recv(&r1), Ok(i)),
+//                     ix if ix == oper2 => assert!(oper.send(&s2, i).is_ok()),
+//                     _ => unreachable!(),
+//                 }
+//             }
+//             s3.send(()).unwrap();
+//         }
+//     })
+//     .unwrap();
+// }
diff --git a/vendor/flume/tests/select_macro.rs b/vendor/flume/tests/select_macro.rs
new file mode 100644
index 0000000..367d8dd
--- /dev/null
+++ b/vendor/flume/tests/select_macro.rs
@@ -0,0 +1,1440 @@
+// //! Tests for the `select!` macro.
+
+// #![deny(unsafe_code)]
+
+// #[macro_use]
+// extern crate crossbeam_channel;
+// extern crate crossbeam_utils;
+
+// use std::any::Any;
+// use std::cell::Cell;
+// use std::ops::Deref;
+// use std::thread;
+// use std::time::{Duration, Instant};
+
+// use crossbeam_channel::{after, bounded, never, tick, unbounded};
+// use crossbeam_channel::{Receiver, RecvError, SendError, Sender, TryRecvError};
+// use crossbeam_utils::thread::scope;
+
+// fn ms(ms: u64) -> Duration {
+//     Duration::from_millis(ms)
+// }
+
+// #[test]
+// fn smoke1() {
+//     let (s1, r1) = unbounded::<usize>();
+//     let (s2, r2) = unbounded::<usize>();
+
+//     s1.send(1).unwrap();
+
+//     select! {
+//         recv(r1) -> v => assert_eq!(v, Ok(1)),
+//         recv(r2) -> _ => panic!(),
+//     }
+
+//     s2.send(2).unwrap();
+
+//     select! {
+//         recv(r1) -> _ => panic!(),
+//         recv(r2) -> v => assert_eq!(v, Ok(2)),
+//     }
+// }
+
+// #[test]
+// fn smoke2() {
+//     let (_s1, r1) = unbounded::<i32>();
+//     let (_s2, r2) = unbounded::<i32>();
+//     let (_s3, r3) = unbounded::<i32>();
+//     let (_s4, r4) = unbounded::<i32>();
+//     let (s5, r5) = unbounded::<i32>();
+
+//     s5.send(5).unwrap();
+
+//     select! {
+//         recv(r1) -> _ => panic!(),
+//         recv(r2) -> _ => panic!(),
+//         recv(r3) -> _ => panic!(),
+//         recv(r4) -> _ => panic!(),
+//         recv(r5) -> v => assert_eq!(v, Ok(5)),
+//     }
+// }
+
+// #[test]
+// fn disconnected() {
+//     let (s1, r1) = unbounded::<i32>();
+//     let (s2, r2) = unbounded::<i32>();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             drop(s1);
+//             thread::sleep(ms(500));
+//             s2.send(5).unwrap();
+//         });
+
+//         select! {
+//             recv(r1) -> v => assert!(v.is_err()),
+//             recv(r2) -> _ => panic!(),
+//             default(ms(1000)) => panic!(),
+//         }
+
+//         r2.recv().unwrap();
+//     })
+//     .unwrap();
+
+//     select! {
+//         recv(r1) -> v => assert!(v.is_err()),
+//         recv(r2) -> _ => panic!(),
+//         default(ms(1000)) => panic!(),
+//     }
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             drop(s2);
+//         });
+
+//         select! {
+//             recv(r2) -> v => assert!(v.is_err()),
+//             default(ms(1000)) => panic!(),
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn default() {
+//     let (s1, r1) = unbounded::<i32>();
+//     let (s2, r2) = unbounded::<i32>();
+
+//     select! {
+//         recv(r1) -> _ => panic!(),
+//         recv(r2) -> _ => panic!(),
+//         default => {}
+//     }
+
+//     drop(s1);
+
+//     select! {
+//         recv(r1) -> v => assert!(v.is_err()),
+//         recv(r2) -> _ => panic!(),
+//         default => panic!(),
+//     }
+
+//     s2.send(2).unwrap();
+
+//     select! {
+//         recv(r2) -> v => assert_eq!(v, Ok(2)),
+//         default => panic!(),
+//     }
+
+//     select! {
+//         recv(r2) -> _ => panic!(),
+//         default => {},
+//     }
+
+//     select! {
+//         default => {},
+//     }
+// }
+
+// #[test]
+// fn timeout() {
+//     let (_s1, r1) = unbounded::<i32>();
+//     let (s2, r2) = unbounded::<i32>();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(1500));
+//             s2.send(2).unwrap();
+//         });
+
+//         select! {
+//             recv(r1) -> _ => panic!(),
+//             recv(r2) -> _ => panic!(),
+//             default(ms(1000)) => {},
+//         }
+
+//         select! {
+//             recv(r1) -> _ => panic!(),
+//             recv(r2) -> v => assert_eq!(v, Ok(2)),
+//             default(ms(1000)) => panic!(),
+//         }
+//     })
+//     .unwrap();
+
+//     scope(|scope| {
+//         let (s, r) = unbounded::<i32>();
+
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(500));
+//             drop(s);
+//         });
+
+//         select! {
+//             default(ms(1000)) => {
+//                 select! {
+//                     recv(r) -> v => assert!(v.is_err()),
+//                     default => panic!(),
+//                 }
+//             }
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn default_when_disconnected() {
+//     let (_, r) = unbounded::<i32>();
+
+//     select! {
+//         recv(r) -> res => assert!(res.is_err()),
+//         default => panic!(),
+//     }
+
+//     let (_, r) = unbounded::<i32>();
+
+//     select! {
+//         recv(r) -> res => assert!(res.is_err()),
+//         default(ms(1000)) => panic!(),
+//     }
+
+//     let (s, _) = bounded::<i32>(0);
+
+//     select! {
+//         send(s, 0) -> res => assert!(res.is_err()),
+//         default => panic!(),
+//     }
+
+//     let (s, _) = bounded::<i32>(0);
+
+//     select! {
+//         send(s, 0) -> res => assert!(res.is_err()),
+//         default(ms(1000)) => panic!(),
+//     }
+// }
+
+// #[test]
+// fn default_only() {
+//     let start = Instant::now();
+//     select! {
+//         default => {}
+//     }
+//     let now = Instant::now();
+//     assert!(now - start <= ms(50));
+
+//     let start = Instant::now();
+//     select! {
+//         default(ms(500)) => {}
+//     }
+//     let now = Instant::now();
+//     assert!(now - start >= ms(450));
+//     assert!(now - start <= ms(550));
+// }
+
+// #[test]
+// fn unblocks() {
+//     let (s1, r1) = bounded::<i32>(0);
+//     let (s2, r2) = bounded::<i32>(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             s2.send(2).unwrap();
+//         });
+
+//         select! {
+//             recv(r1) -> _ => panic!(),
+//             recv(r2) -> v => assert_eq!(v, Ok(2)),
+//             default(ms(1000)) => panic!(),
+//         }
+//     })
+//     .unwrap();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             assert_eq!(r1.recv().unwrap(), 1);
+//         });
+
+//         select! {
+//             send(s1, 1) -> _ => {},
+//             send(s2, 2) -> _ => panic!(),
+//             default(ms(1000)) => panic!(),
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn both_ready() {
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             s1.send(1).unwrap();
+//             assert_eq!(r2.recv().unwrap(), 2);
+//         });
+
+//         for _ in 0..2 {
+//             select! {
+//                 recv(r1) -> v => assert_eq!(v, Ok(1)),
+//                 send(s2, 2) -> _ => {},
+//             }
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn loop_try() {
+//     const RUNS: usize = 20;
+
+//     for _ in 0..RUNS {
+//         let (s1, r1) = bounded::<i32>(0);
+//         let (s2, r2) = bounded::<i32>(0);
+//         let (s_end, r_end) = bounded::<()>(0);
+
+//         scope(|scope| {
+//             scope.spawn(|_| loop {
+//                 select! {
+//                     send(s1, 1) -> _ => break,
+//                     default => {}
+//                 }
+
+//                 select! {
+//                     recv(r_end) -> _ => break,
+//                     default => {}
+//                 }
+//             });
+
+//             scope.spawn(|_| loop {
+//                 if let Ok(x) = r2.try_recv() {
+//                     assert_eq!(x, 2);
+//                     break;
+//                 }
+
+//                 select! {
+//                     recv(r_end) -> _ => break,
+//                     default => {}
+//                 }
+//             });
+
+//             scope.spawn(|_| {
+//                 thread::sleep(ms(500));
+
+//                 select! {
+//                     recv(r1) -> v => assert_eq!(v, Ok(1)),
+//                     send(s2, 2) -> _ => {},
+//                     default(ms(500)) => panic!(),
+//                 }
+
+//                 drop(s_end);
+//             });
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn cloning1() {
+//     scope(|scope| {
+//         let (s1, r1) = unbounded::<i32>();
+//         let (_s2, r2) = unbounded::<i32>();
+//         let (s3, r3) = unbounded::<()>();
+
+//         scope.spawn(move |_| {
+//             r3.recv().unwrap();
+//             drop(s1.clone());
+//             assert_eq!(r3.try_recv(), Err(TryRecvError::Empty));
+//             s1.send(1).unwrap();
+//             r3.recv().unwrap();
+//         });
+
+//         s3.send(()).unwrap();
+
+//         select! {
+//             recv(r1) -> _ => {},
+//             recv(r2) -> _ => {},
+//         }
+
+//         s3.send(()).unwrap();
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn cloning2() {
+//     let (s1, r1) = unbounded::<()>();
+//     let (s2, r2) = unbounded::<()>();
+//     let (_s3, _r3) = unbounded::<()>();
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             select! {
+//                 recv(r1) -> _ => panic!(),
+//                 recv(r2) -> _ => {},
+//             }
+//         });
+
+//         thread::sleep(ms(500));
+//         drop(s1.clone());
+//         s2.send(()).unwrap();
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn preflight1() {
+//     let (s, r) = unbounded();
+//     s.send(()).unwrap();
+
+//     select! {
+//         recv(r) -> _ => {}
+//     }
+// }
+
+// #[test]
+// fn preflight2() {
+//     let (s, r) = unbounded();
+//     drop(s.clone());
+//     s.send(()).unwrap();
+//     drop(s);
+
+//     select! {
+//         recv(r) -> v => assert!(v.is_ok()),
+//     }
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected));
+// }
+
+// #[test]
+// fn preflight3() {
+//     let (s, r) = unbounded();
+//     drop(s.clone());
+//     s.send(()).unwrap();
+//     drop(s);
+//     r.recv().unwrap();
+
+//     select! {
+//         recv(r) -> v => assert!(v.is_err())
+//     }
+// }
+
+// #[test]
+// fn duplicate_operations() {
+//     let (s, r) = unbounded::<i32>();
+//     let mut hit = [false; 4];
+
+//     while hit.iter().any(|hit| !hit) {
+//         select! {
+//             recv(r) -> _ => hit[0] = true,
+//             recv(r) -> _ => hit[1] = true,
+//             send(s, 0) -> _ => hit[2] = true,
+//             send(s, 0) -> _ => hit[3] = true,
+//         }
+//     }
+// }
+
+// #[test]
+// fn nesting() {
+//     let (s, r) = unbounded::<i32>();
+
+//     select! {
+//         send(s, 0) -> _ => {
+//             select! {
+//                 recv(r) -> v => {
+//                     assert_eq!(v, Ok(0));
+//                     select! {
+//                         send(s, 1) -> _ => {
+//                             select! {
+//                                 recv(r) -> v => {
+//                                     assert_eq!(v, Ok(1));
+//                                 }
+//                             }
+//                         }
+//                     }
+//                 }
+//             }
+//         }
+//     }
+// }
+
+// #[test]
+// #[should_panic(expected = "send panicked")]
+// fn panic_sender() {
+//     fn get() -> Sender<i32> {
+//         panic!("send panicked")
+//     }
+
+//     #[allow(unreachable_code)]
+//     {
+//         select! {
+//             send(get(), panic!()) -> _ => {}
+//         }
+//     }
+// }
+
+// #[test]
+// #[should_panic(expected = "recv panicked")]
+// fn panic_receiver() {
+//     fn get() -> Receiver<i32> {
+//         panic!("recv panicked")
+//     }
+
+//     select! {
+//         recv(get()) -> _ => {}
+//     }
+// }
+
+// #[test]
+// fn stress_recv() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = unbounded();
+//     let (s2, r2) = bounded(5);
+//     let (s3, r3) = bounded(100);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 s1.send(i).unwrap();
+//                 r3.recv().unwrap();
+
+//                 s2.send(i).unwrap();
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 select! {
+//                     recv(r1) -> v => assert_eq!(v, Ok(i)),
+//                     recv(r2) -> v => assert_eq!(v, Ok(i)),
+//                 }
+
+//                 s3.send(()).unwrap();
+//             }
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn stress_send() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+//     let (s3, r3) = bounded(100);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 assert_eq!(r1.recv().unwrap(), i);
+//                 assert_eq!(r2.recv().unwrap(), i);
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 select! {
+//                     send(s1, i) -> _ => {},
+//                     send(s2, i) -> _ => {},
+//                 }
+//             }
+//             s3.send(()).unwrap();
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn stress_mixed() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded(0);
+//     let (s2, r2) = bounded(0);
+//     let (s3, r3) = bounded(100);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 s1.send(i).unwrap();
+//                 assert_eq!(r2.recv().unwrap(), i);
+//                 r3.recv().unwrap();
+//             }
+//         });
+
+//         for i in 0..COUNT {
+//             for _ in 0..2 {
+//                 select! {
+//                     recv(r1) -> v => assert_eq!(v, Ok(i)),
+//                     send(s2, i) -> _ => {},
+//                 }
+//             }
+//             s3.send(()).unwrap();
+//         }
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn stress_timeout_two_threads() {
+//     const COUNT: usize = 20;
+
+//     let (s, r) = bounded(2);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 if i % 2 == 0 {
+//                     thread::sleep(ms(500));
+//                 }
+
+//                 loop {
+//                     select! {
+//                         send(s, i) -> _ => break,
+//                         default(ms(100)) => {}
+//                     }
+//                 }
+//             }
+//         });
+
+//         scope.spawn(|_| {
+//             for i in 0..COUNT {
+//                 if i % 2 == 0 {
+//                     thread::sleep(ms(500));
+//                 }
+
+//                 loop {
+//                     select! {
+//                         recv(r) -> v => {
+//                             assert_eq!(v, Ok(i));
+//                             break;
+//                         }
+//                         default(ms(100)) => {}
+//                     }
+//                 }
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn send_recv_same_channel() {
+//     let (s, r) = bounded::<i32>(0);
+//     select! {
+//         send(s, 0) -> _ => panic!(),
+//         recv(r) -> _ => panic!(),
+//         default(ms(500)) => {}
+//     }
+
+//     let (s, r) = unbounded::<i32>();
+//     select! {
+//         send(s, 0) -> _ => {},
+//         recv(r) -> _ => panic!(),
+//         default(ms(500)) => panic!(),
+//     }
+// }
+
+// #[test]
+// fn matching() {
+//     const THREADS: usize = 44;
+
+//     let (s, r) = &bounded::<usize>(0);
+
+//     scope(|scope| {
+//         for i in 0..THREADS {
+//             scope.spawn(move |_| {
+//                 select! {
+//                     recv(r) -> v => assert_ne!(v.unwrap(), i),
+//                     send(s, i) -> _ => {},
+//                 }
+//             });
+//         }
+//     })
+//     .unwrap();
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn matching_with_leftover() {
+//     const THREADS: usize = 55;
+
+//     let (s, r) = &bounded::<usize>(0);
+
+//     scope(|scope| {
+//         for i in 0..THREADS {
+//             scope.spawn(move |_| {
+//                 select! {
+//                     recv(r) -> v => assert_ne!(v.unwrap(), i),
+//                     send(s, i) -> _ => {},
+//                 }
+//             });
+//         }
+//         s.send(!0).unwrap();
+//     })
+//     .unwrap();
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn channel_through_channel() {
+//     const COUNT: usize = 1000;
+
+//     type T = Box<dyn Any + Send>;
+
+//     for cap in 0..3 {
+//         let (s, r) = bounded::<T>(cap);
+
+//         scope(|scope| {
+//             scope.spawn(move |_| {
+//                 let mut s = s;
+
+//                 for _ in 0..COUNT {
+//                     let (new_s, new_r) = bounded(cap);
+//                     let new_r: T = Box::new(Some(new_r));
+
+//                     select! {
+//                         send(s, new_r) -> _ => {}
+//                     }
+
+//                     s = new_s;
+//                 }
+//             });
+
+//             scope.spawn(move |_| {
+//                 let mut r = r;
+
+//                 for _ in 0..COUNT {
+//                     r = select! {
+//                         recv(r) -> msg => {
+//                             msg.unwrap()
+//                                 .downcast_mut::<Option<Receiver<T>>>()
+//                                 .unwrap()
+//                                 .take()
+//                                 .unwrap()
+//                         }
+//                     }
+//                 }
+//             });
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn linearizable_default() {
+//     const COUNT: usize = 100_000;
+
+//     for step in 0..2 {
+//         let (start_s, start_r) = bounded::<()>(0);
+//         let (end_s, end_r) = bounded::<()>(0);
+
+//         let ((s1, r1), (s2, r2)) = if step == 0 {
+//             (bounded::<i32>(1), bounded::<i32>(1))
+//         } else {
+//             (unbounded::<i32>(), unbounded::<i32>())
+//         };
+
+//         scope(|scope| {
+//             scope.spawn(|_| {
+//                 for _ in 0..COUNT {
+//                     start_s.send(()).unwrap();
+
+//                     s1.send(1).unwrap();
+//                     select! {
+//                         recv(r1) -> _ => {}
+//                         recv(r2) -> _ => {}
+//                         default => unreachable!()
+//                     }
+
+//                     end_s.send(()).unwrap();
+//                     let _ = r2.try_recv();
+//                 }
+//             });
+
+//             for _ in 0..COUNT {
+//                 start_r.recv().unwrap();
+
+//                 s2.send(1).unwrap();
+//                 let _ = r1.try_recv();
+
+//                 end_r.recv().unwrap();
+//             }
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn linearizable_timeout() {
+//     const COUNT: usize = 100_000;
+
+//     for step in 0..2 {
+//         let (start_s, start_r) = bounded::<()>(0);
+//         let (end_s, end_r) = bounded::<()>(0);
+
+//         let ((s1, r1), (s2, r2)) = if step == 0 {
+//             (bounded::<i32>(1), bounded::<i32>(1))
+//         } else {
+//             (unbounded::<i32>(), unbounded::<i32>())
+//         };
+
+//         scope(|scope| {
+//             scope.spawn(|_| {
+//                 for _ in 0..COUNT {
+//                     start_s.send(()).unwrap();
+
+//                     s1.send(1).unwrap();
+//                     select! {
+//                         recv(r1) -> _ => {}
+//                         recv(r2) -> _ => {}
+//                         default(ms(0)) => unreachable!()
+//                     }
+
+//                     end_s.send(()).unwrap();
+//                     let _ = r2.try_recv();
+//                 }
+//             });
+
+//             for _ in 0..COUNT {
+//                 start_r.recv().unwrap();
+
+//                 s2.send(1).unwrap();
+//                 let _ = r1.try_recv();
+
+//                 end_r.recv().unwrap();
+//             }
+//         })
+//         .unwrap();
+//     }
+// }
+
+// #[test]
+// fn fairness1() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded::<()>(COUNT);
+//     let (s2, r2) = unbounded::<()>();
+
+//     for _ in 0..COUNT {
+//         s1.send(()).unwrap();
+//         s2.send(()).unwrap();
+//     }
+
+//     let mut hits = [0usize; 4];
+//     for _ in 0..COUNT {
+//         select! {
+//             recv(r1) -> _ => hits[0] += 1,
+//             recv(r2) -> _ => hits[1] += 1,
+//             recv(after(ms(0))) -> _ => hits[2] += 1,
+//             recv(tick(ms(0))) -> _ => hits[3] += 1,
+//         }
+//     }
+//     assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+// }
+
+// #[test]
+// fn fairness2() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = unbounded::<()>();
+//     let (s2, r2) = bounded::<()>(1);
+//     let (s3, r3) = bounded::<()>(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             let (hole, _r) = bounded(0);
+
+//             for _ in 0..COUNT {
+//                 let s1 = if s1.is_empty() { &s1 } else { &hole };
+//                 let s2 = if s2.is_empty() { &s2 } else { &hole };
+
+//                 select! {
+//                     send(s1, ()) -> res => assert!(res.is_ok()),
+//                     send(s2, ()) -> res => assert!(res.is_ok()),
+//                     send(s3, ()) -> res => assert!(res.is_ok()),
+//                 }
+//             }
+//         });
+
+//         let hits = vec![Cell::new(0usize); 3];
+//         for _ in 0..COUNT {
+//             select! {
+//                 recv(r1) -> _ => hits[0].set(hits[0].get() + 1),
+//                 recv(r2) -> _ => hits[1].set(hits[1].get() + 1),
+//                 recv(r3) -> _ => hits[2].set(hits[2].get() + 1),
+//             }
+//         }
+//         assert!(hits.iter().all(|x| x.get() >= COUNT / hits.len() / 50));
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn fairness_recv() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded::<()>(COUNT);
+//     let (s2, r2) = unbounded::<()>();
+
+//     for _ in 0..COUNT {
+//         s1.send(()).unwrap();
+//         s2.send(()).unwrap();
+//     }
+
+//     let mut hits = [0usize; 2];
+//     while hits[0] + hits[1] < COUNT {
+//         select! {
+//             recv(r1) -> _ => hits[0] += 1,
+//             recv(r2) -> _ => hits[1] += 1,
+//         }
+//     }
+//     assert!(hits.iter().all(|x| *x >= COUNT / 4));
+// }
+
+// #[test]
+// fn fairness_send() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, _r1) = bounded::<()>(COUNT);
+//     let (s2, _r2) = unbounded::<()>();
+
+//     let mut hits = [0usize; 2];
+//     for _ in 0..COUNT {
+//         select! {
+//             send(s1, ()) -> _ => hits[0] += 1,
+//             send(s2, ()) -> _ => hits[1] += 1,
+//         }
+//     }
+//     assert!(hits.iter().all(|x| *x >= COUNT / 4));
+// }
+
+// #[test]
+// fn references() {
+//     let (s, r) = unbounded::<i32>();
+//     select! {
+//         send(s, 0) -> _ => {}
+//         recv(r) -> _ => {}
+//     }
+//     select! {
+//         send(&&&&s, 0) -> _ => {}
+//         recv(&&&&r) -> _ => {}
+//     }
+//     select! {
+//         recv(Some(&r).unwrap_or(&never())) -> _ => {},
+//         default => {}
+//     }
+//     select! {
+//         recv(Some(r).unwrap_or(never())) -> _ => {},
+//         default => {}
+//     }
+// }
+
+// #[test]
+// fn case_blocks() {
+//     let (s, r) = unbounded::<i32>();
+
+//     select! {
+//         recv(r) -> _ => 3.0,
+//         recv(r) -> _ => loop {
+//             unreachable!()
+//         },
+//         recv(r) -> _ => match 7 + 3 {
+//             _ => unreachable!()
+//         },
+//         default => 7.
+//     };
+
+//     select! {
+//         recv(r) -> msg => if msg.is_ok() {
+//             unreachable!()
+//         },
+//         default => ()
+//     }
+
+//     drop(s);
+// }
+
+// #[test]
+// fn move_handles() {
+//     let (s, r) = unbounded::<i32>();
+//     select! {
+//         recv((move || r)()) -> _ => {}
+//         send((move || s)(), 0) -> _ => {}
+//     }
+// }
+
+// #[test]
+// fn infer_types() {
+//     let (s, r) = unbounded();
+//     select! {
+//         recv(r) -> _ => {}
+//         default => {}
+//     }
+//     s.send(()).unwrap();
+
+//     let (s, r) = unbounded();
+//     select! {
+//         send(s, ()) -> _ => {}
+//     }
+//     r.recv().unwrap();
+// }
+
+// #[test]
+// fn default_syntax() {
+//     let (s, r) = bounded::<i32>(0);
+
+//     select! {
+//         recv(r) -> _ => panic!(),
+//         default => {}
+//     }
+//     select! {
+//         send(s, 0) -> _ => panic!(),
+//         default() => {}
+//     }
+//     select! {
+//         default => {}
+//     }
+//     select! {
+//         default() => {}
+//     }
+// }
+
+// #[test]
+// fn same_variable_name() {
+//     let (_, r) = unbounded::<i32>();
+//     select! {
+//         recv(r) -> r => assert!(r.is_err()),
+//     }
+// }
+
+// #[test]
+// fn handles_on_heap() {
+//     let (s, r) = unbounded::<i32>();
+//     let (s, r) = (Box::new(s), Box::new(r));
+
+//     select! {
+//         send(*s, 0) -> _ => {}
+//         recv(*r) -> _ => {}
+//         default => {}
+//     }
+
+//     drop(s);
+//     drop(r);
+// }
+
+// #[test]
+// fn once_blocks() {
+//     let (s, r) = unbounded::<i32>();
+
+//     let once = Box::new(());
+//     select! {
+//         send(s, 0) -> _ => drop(once),
+//     }
+
+//     let once = Box::new(());
+//     select! {
+//         recv(r) -> _ => drop(once),
+//     }
+
+//     let once1 = Box::new(());
+//     let once2 = Box::new(());
+//     select! {
+//         send(s, 0) -> _ => drop(once1),
+//         default => drop(once2),
+//     }
+
+//     let once1 = Box::new(());
+//     let once2 = Box::new(());
+//     select! {
+//         recv(r) -> _ => drop(once1),
+//         default => drop(once2),
+//     }
+
+//     let once1 = Box::new(());
+//     let once2 = Box::new(());
+//     select! {
+//         recv(r) -> _ => drop(once1),
+//         send(s, 0) -> _ => drop(once2),
+//     }
+// }
+
+// #[test]
+// fn once_receiver() {
+//     let (_, r) = unbounded::<i32>();
+
+//     let once = Box::new(());
+//     let get = move || {
+//         drop(once);
+//         r
+//     };
+
+//     select! {
+//         recv(get()) -> _ => {}
+//     }
+// }
+
+// #[test]
+// fn once_sender() {
+//     let (s, _) = unbounded::<i32>();
+
+//     let once = Box::new(());
+//     let get = move || {
+//         drop(once);
+//         s
+//     };
+
+//     select! {
+//         send(get(), 5) -> _ => {}
+//     }
+// }
+
+// #[test]
+// fn parse_nesting() {
+//     let (_, r) = unbounded::<i32>();
+
+//     select! {
+//         recv(r) -> _ => {}
+//         recv(r) -> _ => {
+//             select! {
+//                 recv(r) -> _ => {}
+//                 recv(r) -> _ => {
+//                     select! {
+//                         recv(r) -> _ => {}
+//                         recv(r) -> _ => {
+//                             select! {
+//                                 default => {}
+//                             }
+//                         }
+//                     }
+//                 }
+//             }
+//         }
+//     }
+// }
+
+// #[test]
+// fn evaluate() {
+//     let (s, r) = unbounded::<i32>();
+
+//     let v = select! {
+//         recv(r) -> _ => "foo".into(),
+//         send(s, 0) -> _ => "bar".to_owned(),
+//         default => "baz".to_string(),
+//     };
+//     assert_eq!(v, "bar");
+
+//     let v = select! {
+//         recv(r) -> _ => "foo".into(),
+//         default => "baz".to_string(),
+//     };
+//     assert_eq!(v, "foo");
+
+//     let v = select! {
+//         recv(r) -> _ => "foo".into(),
+//         default => "baz".to_string(),
+//     };
+//     assert_eq!(v, "baz");
+// }
+
+// #[test]
+// fn deref() {
+//     use crossbeam_channel as cc;
+
+//     struct Sender<T>(cc::Sender<T>);
+//     struct Receiver<T>(cc::Receiver<T>);
+
+//     impl<T> Deref for Receiver<T> {
+//         type Target = cc::Receiver<T>;
+
+//         fn deref(&self) -> &Self::Target {
+//             &self.0
+//         }
+//     }
+
+//     impl<T> Deref for Sender<T> {
+//         type Target = cc::Sender<T>;
+
+//         fn deref(&self) -> &Self::Target {
+//             &self.0
+//         }
+//     }
+
+//     let (s, r) = bounded::<i32>(0);
+//     let (s, r) = (Sender(s), Receiver(r));
+
+//     select! {
+//         send(s, 0) -> _ => panic!(),
+//         recv(r) -> _ => panic!(),
+//         default => {}
+//     }
+// }
+
+// #[test]
+// fn result_types() {
+//     let (s, _) = bounded::<i32>(0);
+//     let (_, r) = bounded::<i32>(0);
+
+//     select! {
+//         recv(r) -> res => drop::<Result<i32, RecvError>>(res),
+//     }
+//     select! {
+//         recv(r) -> res => drop::<Result<i32, RecvError>>(res),
+//         default => {}
+//     }
+//     select! {
+//         recv(r) -> res => drop::<Result<i32, RecvError>>(res),
+//         default(ms(0)) => {}
+//     }
+
+//     select! {
+//         send(s, 0) -> res => drop::<Result<(), SendError<i32>>>(res),
+//     }
+//     select! {
+//         send(s, 0) -> res => drop::<Result<(), SendError<i32>>>(res),
+//         default => {}
+//     }
+//     select! {
+//         send(s, 0) -> res => drop::<Result<(), SendError<i32>>>(res),
+//         default(ms(0)) => {}
+//     }
+
+//     select! {
+//         send(s, 0) -> res => drop::<Result<(), SendError<i32>>>(res),
+//         recv(r) -> res => drop::<Result<i32, RecvError>>(res),
+//     }
+// }
+
+// #[test]
+// fn try_recv() {
+//     let (s, r) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             select! {
+//                 recv(r) -> _ => panic!(),
+//                 default => {}
+//             }
+//             thread::sleep(ms(1500));
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(7)),
+//                 default => panic!(),
+//             }
+//             thread::sleep(ms(500));
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Err(RecvError)),
+//                 default => panic!(),
+//             }
+//         });
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(1000));
+//             select! {
+//                 send(s, 7) -> res => res.unwrap(),
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn recv() {
+//     let (s, r) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(7)),
+//             }
+//             thread::sleep(ms(1000));
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(8)),
+//             }
+//             thread::sleep(ms(1000));
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(9)),
+//             }
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Err(RecvError)),
+//             }
+//         });
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(1500));
+//             select! {
+//                 send(s, 7) -> res => res.unwrap(),
+//             }
+//             select! {
+//                 send(s, 8) -> res => res.unwrap(),
+//             }
+//             select! {
+//                 send(s, 9) -> res => res.unwrap(),
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn recv_timeout() {
+//     let (s, r) = bounded::<i32>(0);
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             select! {
+//                 recv(r) -> _ => panic!(),
+//                 default(ms(1000)) => {}
+//             }
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(7)),
+//                 default(ms(1000)) => panic!(),
+//             }
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Err(RecvError)),
+//                 default(ms(1000)) => panic!(),
+//             }
+//         });
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(1500));
+//             select! {
+//                 send(s, 7) -> res => res.unwrap(),
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn try_send() {
+//     let (s, r) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             select! {
+//                 send(s, 7) -> _ => panic!(),
+//                 default => {}
+//             }
+//             thread::sleep(ms(1500));
+//             select! {
+//                 send(s, 8) -> res => res.unwrap(),
+//                 default => panic!(),
+//             }
+//             thread::sleep(ms(500));
+//             select! {
+//                 send(s, 8) -> res => assert_eq!(res, Err(SendError(8))),
+//                 default => panic!(),
+//             }
+//         });
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(1000));
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(8)),
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn send() {
+//     let (s, r) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             select! {
+//                 send(s, 7) -> res => res.unwrap(),
+//             }
+//             thread::sleep(ms(1000));
+//             select! {
+//                 send(s, 8) -> res => res.unwrap(),
+//             }
+//             thread::sleep(ms(1000));
+//             select! {
+//                 send(s, 9) -> res => res.unwrap(),
+//             }
+//         });
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(1500));
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(7)),
+//             }
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(8)),
+//             }
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(9)),
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn send_timeout() {
+//     let (s, r) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             select! {
+//                 send(s, 7) -> _ => panic!(),
+//                 default(ms(1000)) => {}
+//             }
+//             select! {
+//                 send(s, 8) -> res => res.unwrap(),
+//                 default(ms(1000)) => panic!(),
+//             }
+//             select! {
+//                 send(s, 9) -> res => assert_eq!(res, Err(SendError(9))),
+//                 default(ms(1000)) => panic!(),
+//             }
+//         });
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(1500));
+//             select! {
+//                 recv(r) -> v => assert_eq!(v, Ok(8)),
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn disconnect_wakes_sender() {
+//     let (s, r) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             select! {
+//                 send(s, ()) -> res => assert_eq!(res, Err(SendError(()))),
+//             }
+//         });
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(1000));
+//             drop(r);
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn disconnect_wakes_receiver() {
+//     let (s, r) = bounded::<()>(0);
+
+//     scope(|scope| {
+//         scope.spawn(move |_| {
+//             select! {
+//                 recv(r) -> res => assert_eq!(res, Err(RecvError)),
+//             }
+//         });
+//         scope.spawn(move |_| {
+//             thread::sleep(ms(1000));
+//             drop(s);
+//         });
+//     })
+//     .unwrap();
+// }
diff --git a/vendor/flume/tests/stream.rs b/vendor/flume/tests/stream.rs
new file mode 100644
index 0000000..e3b32cd
--- /dev/null
+++ b/vendor/flume/tests/stream.rs
@@ -0,0 +1,255 @@
+#[cfg(feature = "async")]
+use {
+    flume::*,
+    futures::{stream::FuturesUnordered, StreamExt, TryFutureExt},
+    async_std::prelude::FutureExt,
+    std::time::Duration,
+};
+use futures::{stream, Stream};
+
+#[cfg(feature = "async")]
+#[test]
+fn stream_recv() {
+    let (tx, rx) = unbounded();
+
+    let t = std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(250));
+        tx.send(42u32).unwrap();
+        println!("sent");
+    });
+
+    async_std::task::block_on(async {
+        println!("receiving...");
+        let x = rx.stream().next().await;
+        println!("received");
+        assert_eq!(x, Some(42));
+    });
+
+    t.join().unwrap();
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn stream_recv_disconnect() {
+    let (tx, rx) = bounded::<i32>(0);
+
+    let t = std::thread::spawn(move || {
+        tx.send(42);
+        std::thread::sleep(std::time::Duration::from_millis(250));
+        drop(tx)
+    });
+
+    async_std::task::block_on(async {
+        let mut stream = rx.into_stream();
+        assert_eq!(stream.next().await, Some(42));
+        assert_eq!(stream.next().await, None);
+    });
+
+    t.join().unwrap();
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn stream_recv_drop_recv() {
+    let (tx, rx) = bounded::<i32>(10);
+
+    let rx2 = rx.clone();
+    let mut stream = rx.into_stream();
+
+    async_std::task::block_on(async {
+        let res = async_std::future::timeout(
+            std::time::Duration::from_millis(500),
+            stream.next()
+        ).await;
+
+        assert!(res.is_err());
+    });
+
+    let t = std::thread::spawn(move || {
+        async_std::task::block_on(async {
+            rx2.stream().next().await
+        })
+    });
+
+    std::thread::sleep(std::time::Duration::from_millis(500));
+
+    tx.send(42).unwrap();
+
+    drop(stream);
+
+    assert_eq!(t.join().unwrap(), Some(42))
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn r#stream_drop_send_disconnect() {
+    let (tx, rx) = bounded::<i32>(1);
+
+    let t = std::thread::spawn(move || {
+        std::thread::sleep(std::time::Duration::from_millis(250));
+        drop(tx);
+    });
+
+    async_std::task::block_on(async {
+        let mut stream = rx.into_stream();
+        assert_eq!(stream.next().await, None);
+    });
+
+    t.join().unwrap();
+}
+
+#[cfg(feature = "async")]
+#[async_std::test]
+async fn stream_send_1_million_no_drop_or_reorder() {
+    #[derive(Debug)]
+    enum Message {
+        Increment {
+            old: u64,
+        },
+        ReturnCount,
+    }
+
+    let (tx, rx) = unbounded();
+
+    let t = async_std::task::spawn(async move {
+        let mut count = 0u64;
+        let mut stream = rx.into_stream();
+
+        while let Some(Message::Increment { old }) = stream.next().await {
+            assert_eq!(old, count);
+            count += 1;
+        }
+
+        count
+    });
+
+    for next in 0..1_000_000 {
+        tx.send(Message::Increment { old: next }).unwrap();
+    }
+
+    tx.send(Message::ReturnCount).unwrap();
+
+    let count = t.await;
+    assert_eq!(count, 1_000_000)
+}
+
+#[cfg(feature = "async")]
+#[async_std::test]
+async fn parallel_streams_and_async_recv() {
+    let (tx, rx) = flume::unbounded();
+    let rx = &rx;
+    let send_fut = async move {
+        let n_sends: usize = 100000;
+        for _ in 0..n_sends {
+            tx.send_async(()).await.unwrap();
+        }
+    };
+
+    async_std::task::spawn(
+        send_fut
+            .timeout(Duration::from_secs(5))
+            .map_err(|_| panic!("Send timed out!"))
+    );
+
+    let mut futures_unordered = (0..250)
+        .map(|n| async move {
+            if n % 2 == 0 {
+                let mut stream = rx.stream();
+                while let Some(()) = stream.next().await {}
+            } else {
+                while let Ok(()) = rx.recv_async().await {}
+            }
+
+        })
+        .collect::<FuturesUnordered<_>>();
+
+    let recv_fut = async {
+        while futures_unordered.next().await.is_some() {}
+    };
+
+    recv_fut
+        .timeout(Duration::from_secs(5))
+        .map_err(|_| panic!("Receive timed out!"))
+        .await
+        .unwrap();
+}
+
+#[cfg(feature = "async")]
+#[test]
+fn stream_no_double_wake() {
+    use std::sync::atomic::{AtomicUsize, Ordering};
+    use std::sync::Arc;
+    use std::pin::Pin;
+    use std::task::Context;
+    use futures::task::{waker, ArcWake};
+    use futures::Stream;
+
+    let count = Arc::new(AtomicUsize::new(0));
+
+    // all this waker does is count how many times it is called
+    struct CounterWaker {
+        count: Arc<AtomicUsize>,
+    }
+
+    impl ArcWake for CounterWaker {
+        fn wake_by_ref(arc_self: &Arc<Self>) {
+            arc_self.count.fetch_add(1, Ordering::SeqCst);
+        }
+    }
+
+    // create waker and context
+    let w = CounterWaker {
+        count: count.clone(),
+    };
+    let w = waker(Arc::new(w));
+    let cx = &mut Context::from_waker(&w);
+
+    // create unbounded channel
+    let (tx, rx) = unbounded::<()>();
+    let mut stream = rx.stream();
+
+    // register waker with stream
+    let _ = Pin::new(&mut stream).poll_next(cx);
+
+    // send multiple items
+    tx.send(()).unwrap();
+    tx.send(()).unwrap();
+    tx.send(()).unwrap();
+
+    // verify that stream is only woken up once.
+    assert_eq!(count.load(Ordering::SeqCst), 1);
+}
+
+#[cfg(feature = "async")]
+#[async_std::test]
+async fn stream_forward_issue_55() { // https://github.com/zesterer/flume/issues/55
+    fn dummy_stream() -> impl Stream<Item = usize> {
+        stream::unfold(0, |count| async move {
+            if count < 1000 {
+                Some((count, count + 1))
+            } else {
+                None
+            }
+        })
+    }
+
+    let (send_task, recv_task) = {
+        use futures::SinkExt;
+        let (tx, rx) = flume::bounded(100);
+
+        let send_task = dummy_stream()
+            .map(|i| Ok(i))
+            .forward(tx.into_sink().sink_map_err(|e| {
+                panic!("send error:{:#?}", e)
+            }));
+
+        let recv_task = rx
+            .into_stream()
+            .for_each(|item| async move {});
+        (send_task, recv_task)
+    };
+
+    let jh = async_std::task::spawn(send_task);
+    async_std::task::block_on(recv_task);
+    jh.await.unwrap();
+}
diff --git a/vendor/flume/tests/thread_locals.rs b/vendor/flume/tests/thread_locals.rs
new file mode 100644
index 0000000..acde751
--- /dev/null
+++ b/vendor/flume/tests/thread_locals.rs
@@ -0,0 +1,53 @@
+// //! Tests that make sure accessing thread-locals while exiting the thread doesn't cause panics.
+
+// extern crate crossbeam_utils;
+
+// use std::thread;
+// use std::time::Duration;
+
+// use flume::unbounded;
+// use crossbeam_utils::thread::scope;
+
+// fn ms(ms: u64) -> Duration {
+//     Duration::from_millis(ms)
+// }
+
+// #[test]
+// #[cfg_attr(target_os = "macos", ignore = "TLS is destroyed too early on macOS")]
+// fn use_while_exiting() {
+//     struct Foo;
+
+//     impl Drop for Foo {
+//         fn drop(&mut self) {
+//             // A blocking operation after the thread-locals have been dropped. This will attempt to
+//             // use the thread-locals and must not panic.
+//             let (_s, r) = unbounded::<()>();
+//             select! {
+//                 recv(r) -> _ => {}
+//                 default(ms(100)) => {}
+//             }
+//         }
+//     }
+
+//     thread_local! {
+//         static FOO: Foo = Foo;
+//     }
+
+//     let (s, r) = unbounded::<()>();
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             // First initialize `FOO`, then the thread-locals related to crossbeam-channel.
+//             FOO.with(|_| ());
+//             r.recv().unwrap();
+//             // At thread exit, thread-locals related to crossbeam-channel get dropped first and
+//             // `FOO` is dropped last.
+//         });
+
+//         scope.spawn(|_| {
+//             thread::sleep(ms(100));
+//             s.send(()).unwrap();
+//         });
+//     })
+//     .unwrap();
+// }
diff --git a/vendor/flume/tests/tick.rs b/vendor/flume/tests/tick.rs
new file mode 100644
index 0000000..b0fcd44
--- /dev/null
+++ b/vendor/flume/tests/tick.rs
@@ -0,0 +1,353 @@
+// //! Tests for the tick channel flavor.
+
+// #[macro_use]
+// extern crate crossbeam_channel;
+// extern crate crossbeam_utils;
+// extern crate rand;
+
+// use std::sync::atomic::AtomicUsize;
+// use std::sync::atomic::Ordering;
+// use std::thread;
+// use std::time::{Duration, Instant};
+
+// use crossbeam_channel::{after, tick, Select, TryRecvError};
+// use crossbeam_utils::thread::scope;
+
+// fn ms(ms: u64) -> Duration {
+//     Duration::from_millis(ms)
+// }
+
+// #[test]
+// fn fire() {
+//     let start = Instant::now();
+//     let r = tick(ms(50));
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+//     thread::sleep(ms(100));
+
+//     let fired = r.try_recv().unwrap();
+//     assert!(start < fired);
+//     assert!(fired - start >= ms(50));
+
+//     let now = Instant::now();
+//     assert!(fired < now);
+//     assert!(now - fired >= ms(50));
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+
+//     select! {
+//         recv(r) -> _ => panic!(),
+//         default => {}
+//     }
+
+//     select! {
+//         recv(r) -> _ => {}
+//         recv(tick(ms(200))) -> _ => panic!(),
+//     }
+// }
+
+// #[test]
+// fn intervals() {
+//     let start = Instant::now();
+//     let r = tick(ms(50));
+
+//     let t1 = r.recv().unwrap();
+//     assert!(start + ms(50) <= t1);
+//     assert!(start + ms(100) > t1);
+
+//     thread::sleep(ms(300));
+//     let t2 = r.try_recv().unwrap();
+//     assert!(start + ms(100) <= t2);
+//     assert!(start + ms(150) > t2);
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+//     let t3 = r.recv().unwrap();
+//     assert!(start + ms(400) <= t3);
+//     assert!(start + ms(450) > t3);
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn capacity() {
+//     const COUNT: usize = 10;
+
+//     for i in 0..COUNT {
+//         let r = tick(ms(i as u64));
+//         assert_eq!(r.capacity(), Some(1));
+//     }
+// }
+
+// #[test]
+// fn len_empty_full() {
+//     let r = tick(ms(50));
+
+//     assert_eq!(r.len(), 0);
+//     assert_eq!(r.is_empty(), true);
+//     assert_eq!(r.is_full(), false);
+
+//     thread::sleep(ms(100));
+
+//     assert_eq!(r.len(), 1);
+//     assert_eq!(r.is_empty(), false);
+//     assert_eq!(r.is_full(), true);
+
+//     r.try_recv().unwrap();
+
+//     assert_eq!(r.len(), 0);
+//     assert_eq!(r.is_empty(), true);
+//     assert_eq!(r.is_full(), false);
+// }
+
+// #[test]
+// fn try_recv() {
+//     let r = tick(ms(200));
+//     assert!(r.try_recv().is_err());
+
+//     thread::sleep(ms(100));
+//     assert!(r.try_recv().is_err());
+
+//     thread::sleep(ms(200));
+//     assert!(r.try_recv().is_ok());
+//     assert!(r.try_recv().is_err());
+
+//     thread::sleep(ms(200));
+//     assert!(r.try_recv().is_ok());
+//     assert!(r.try_recv().is_err());
+// }
+
+// #[test]
+// fn recv() {
+//     let start = Instant::now();
+//     let r = tick(ms(50));
+
+//     let fired = r.recv().unwrap();
+//     assert!(start < fired);
+//     assert!(fired - start >= ms(50));
+
+//     let now = Instant::now();
+//     assert!(fired < now);
+//     assert!(now - fired < fired - start);
+
+//     assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+// }
+
+// #[test]
+// fn recv_timeout() {
+//     let start = Instant::now();
+//     let r = tick(ms(200));
+
+//     assert!(r.recv_timeout(ms(100)).is_err());
+//     let now = Instant::now();
+//     assert!(now - start >= ms(100));
+//     assert!(now - start <= ms(150));
+
+//     let fired = r.recv_timeout(ms(200)).unwrap();
+//     assert!(fired - start >= ms(200));
+//     assert!(fired - start <= ms(250));
+
+//     assert!(r.recv_timeout(ms(100)).is_err());
+//     let now = Instant::now();
+//     assert!(now - start >= ms(300));
+//     assert!(now - start <= ms(350));
+
+//     let fired = r.recv_timeout(ms(200)).unwrap();
+//     assert!(fired - start >= ms(400));
+//     assert!(fired - start <= ms(450));
+// }
+
+// #[test]
+// fn recv_two() {
+//     let r1 = tick(ms(50));
+//     let r2 = tick(ms(50));
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             for _ in 0..10 {
+//                 select! {
+//                     recv(r1) -> _ => {}
+//                     recv(r2) -> _ => {}
+//                 }
+//             }
+//         });
+//         scope.spawn(|_| {
+//             for _ in 0..10 {
+//                 select! {
+//                     recv(r1) -> _ => {}
+//                     recv(r2) -> _ => {}
+//                 }
+//             }
+//         });
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn recv_race() {
+//     select! {
+//         recv(tick(ms(50))) -> _ => {}
+//         recv(tick(ms(100))) -> _ => panic!(),
+//     }
+
+//     select! {
+//         recv(tick(ms(100))) -> _ => panic!(),
+//         recv(tick(ms(50))) -> _ => {}
+//     }
+// }
+
+// #[test]
+// fn stress_default() {
+//     const COUNT: usize = 10;
+
+//     for _ in 0..COUNT {
+//         select! {
+//             recv(tick(ms(0))) -> _ => {}
+//             default => panic!(),
+//         }
+//     }
+
+//     for _ in 0..COUNT {
+//         select! {
+//             recv(tick(ms(100))) -> _ => panic!(),
+//             default => {}
+//         }
+//     }
+// }
+
+// #[test]
+// fn select() {
+//     const THREADS: usize = 4;
+
+//     let hits = AtomicUsize::new(0);
+//     let r1 = tick(ms(200));
+//     let r2 = tick(ms(300));
+
+//     scope(|scope| {
+//         for _ in 0..THREADS {
+//             scope.spawn(|_| {
+//                 let timeout = after(ms(1100));
+//                 loop {
+//                     let mut sel = Select::new();
+//                     let oper1 = sel.recv(&r1);
+//                     let oper2 = sel.recv(&r2);
+//                     let oper3 = sel.recv(&timeout);
+//                     let oper = sel.select();
+//                     match oper.index() {
+//                         i if i == oper1 => {
+//                             oper.recv(&r1).unwrap();
+//                             hits.fetch_add(1, Ordering::SeqCst);
+//                         }
+//                         i if i == oper2 => {
+//                             oper.recv(&r2).unwrap();
+//                             hits.fetch_add(1, Ordering::SeqCst);
+//                         }
+//                         i if i == oper3 => {
+//                             oper.recv(&timeout).unwrap();
+//                             break;
+//                         }
+//                         _ => unreachable!(),
+//                     }
+//                 }
+//             });
+//         }
+//     })
+//     .unwrap();
+
+//     assert_eq!(hits.load(Ordering::SeqCst), 8);
+// }
+
+// #[test]
+// fn ready() {
+//     const THREADS: usize = 4;
+
+//     let hits = AtomicUsize::new(0);
+//     let r1 = tick(ms(200));
+//     let r2 = tick(ms(300));
+
+//     scope(|scope| {
+//         for _ in 0..THREADS {
+//             scope.spawn(|_| {
+//                 let timeout = after(ms(1100));
+//                 'outer: loop {
+//                     let mut sel = Select::new();
+//                     sel.recv(&r1);
+//                     sel.recv(&r2);
+//                     sel.recv(&timeout);
+//                     loop {
+//                         match sel.ready() {
+//                             0 => {
+//                                 if r1.try_recv().is_ok() {
+//                                     hits.fetch_add(1, Ordering::SeqCst);
+//                                     break;
+//                                 }
+//                             }
+//                             1 => {
+//                                 if r2.try_recv().is_ok() {
+//                                     hits.fetch_add(1, Ordering::SeqCst);
+//                                     break;
+//                                 }
+//                             }
+//                             2 => {
+//                                 if timeout.try_recv().is_ok() {
+//                                     break 'outer;
+//                                 }
+//                             }
+//                             _ => unreachable!(),
+//                         }
+//                     }
+//                 }
+//             });
+//         }
+//     })
+//     .unwrap();
+
+//     assert_eq!(hits.load(Ordering::SeqCst), 8);
+// }
+
+// #[test]
+// fn fairness() {
+//     const COUNT: usize = 30;
+
+//     for &dur in &[0, 1] {
+//         let mut hits = [0usize; 2];
+
+//         for _ in 0..COUNT {
+//             let r1 = tick(ms(dur));
+//             let r2 = tick(ms(dur));
+
+//             for _ in 0..COUNT {
+//                 select! {
+//                     recv(r1) -> _ => hits[0] += 1,
+//                     recv(r2) -> _ => hits[1] += 1,
+//                 }
+//             }
+//         }
+
+//         assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+//     }
+// }
+
+// #[test]
+// fn fairness_duplicates() {
+//     const COUNT: usize = 30;
+
+//     for &dur in &[0, 1] {
+//         let mut hits = [0usize; 5];
+
+//         for _ in 0..COUNT {
+//             let r = tick(ms(dur));
+
+//             for _ in 0..COUNT {
+//                 select! {
+//                     recv(r) -> _ => hits[0] += 1,
+//                     recv(r) -> _ => hits[1] += 1,
+//                     recv(r) -> _ => hits[2] += 1,
+//                     recv(r) -> _ => hits[3] += 1,
+//                     recv(r) -> _ => hits[4] += 1,
+//                 }
+//             }
+//         }
+
+//         assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+//     }
+// }
diff --git a/vendor/flume/tests/zero.rs b/vendor/flume/tests/zero.rs
new file mode 100644
index 0000000..be4239d
--- /dev/null
+++ b/vendor/flume/tests/zero.rs
@@ -0,0 +1,557 @@
+//! Tests for the zero channel flavor.
+
+extern crate crossbeam_utils;
+extern crate rand;
+
+use std::any::Any;
+use std::sync::atomic::AtomicUsize;
+use std::sync::atomic::Ordering;
+use std::thread;
+use std::time::Duration;
+
+use flume::{bounded, Receiver};
+use flume::{RecvError, RecvTimeoutError, TryRecvError};
+use flume::{SendError, SendTimeoutError, TrySendError};
+use crossbeam_utils::thread::scope;
+use rand::{thread_rng, Rng};
+
+fn ms(ms: u64) -> Duration {
+    Duration::from_millis(ms)
+}
+
+#[test]
+fn smoke() {
+    let (s, r) = bounded(0);
+    assert_eq!(s.try_send(7), Err(TrySendError::Full(7)));
+    assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+}
+
+#[test]
+fn capacity() {
+    let (s, r) = bounded::<()>(0);
+    assert_eq!(s.capacity(), Some(0));
+    assert_eq!(r.capacity(), Some(0));
+}
+
+#[test]
+fn len_empty_full() {
+    let (s, r) = bounded(0);
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(s.is_empty(), true);
+    assert_eq!(s.is_full(), true);
+    assert_eq!(r.len(), 0);
+    assert_eq!(r.is_empty(), true);
+    assert_eq!(r.is_full(), true);
+
+    scope(|scope| {
+        scope.spawn(|_| s.send(0).unwrap());
+        scope.spawn(|_| r.recv().unwrap());
+    })
+    .unwrap();
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(s.is_empty(), true);
+    assert_eq!(s.is_full(), true);
+    assert_eq!(r.len(), 0);
+    assert_eq!(r.is_empty(), true);
+    assert_eq!(r.is_full(), true);
+}
+
+#[test]
+fn try_recv() {
+    let (s, r) = bounded(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(r.try_recv(), Err(TryRecvError::Empty));
+            thread::sleep(ms(1500));
+            assert_eq!(r.try_recv(), Ok(7));
+            thread::sleep(ms(500));
+            assert_eq!(r.try_recv(), Err(TryRecvError::Disconnected));
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            s.send(7).unwrap();
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn recv() {
+    let (s, r) = bounded(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(r.recv(), Ok(7));
+            thread::sleep(ms(1000));
+            assert_eq!(r.recv(), Ok(8));
+            thread::sleep(ms(1000));
+            assert_eq!(r.recv(), Ok(9));
+            assert!(r.recv().is_err());
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1500));
+            s.send(7).unwrap();
+            s.send(8).unwrap();
+            s.send(9).unwrap();
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn recv_timeout() {
+    let (s, r) = bounded::<i32>(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(r.recv_timeout(ms(1000)), Err(RecvTimeoutError::Timeout));
+            assert_eq!(r.recv_timeout(ms(1000)), Ok(7));
+            assert_eq!(
+                r.recv_timeout(ms(1000)),
+                Err(RecvTimeoutError::Disconnected)
+            );
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1500));
+            s.send(7).unwrap();
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn try_send() {
+    let (s, r) = bounded(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(s.try_send(7), Err(TrySendError::Full(7)));
+            thread::sleep(ms(1500));
+            assert_eq!(s.try_send(8), Ok(()));
+            thread::sleep(ms(500));
+            assert_eq!(s.try_send(9), Err(TrySendError::Disconnected(9)));
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            assert_eq!(r.recv(), Ok(8));
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn send() {
+    let (s, r) = bounded(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            s.send(7).unwrap();
+            thread::sleep(ms(1000));
+            s.send(8).unwrap();
+            thread::sleep(ms(1000));
+            s.send(9).unwrap();
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1500));
+            assert_eq!(r.recv(), Ok(7));
+            assert_eq!(r.recv(), Ok(8));
+            assert_eq!(r.recv(), Ok(9));
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn send_timeout() {
+    let (s, r) = bounded(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(
+                s.send_timeout(7, ms(1000)),
+                Err(SendTimeoutError::Timeout(7))
+            );
+            assert_eq!(s.send_timeout(8, ms(1000)), Ok(()));
+            assert_eq!(
+                s.send_timeout(9, ms(1000)),
+                Err(SendTimeoutError::Disconnected(9))
+            );
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1500));
+            assert_eq!(r.recv(), Ok(8));
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn len() {
+    const COUNT: usize = 25_000;
+
+    let (s, r) = bounded(0);
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(r.len(), 0);
+
+    scope(|scope| {
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                assert_eq!(r.recv(), Ok(i));
+                assert_eq!(r.len(), 0);
+            }
+        });
+
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                s.send(i).unwrap();
+                assert_eq!(s.len(), 0);
+            }
+        });
+    })
+    .unwrap();
+
+    assert_eq!(s.len(), 0);
+    assert_eq!(r.len(), 0);
+}
+
+#[test]
+fn disconnect_wakes_sender() {
+    let (s, r) = bounded(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert_eq!(s.send(()), Err(SendError(())));
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            drop(r);
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn disconnect_wakes_receiver() {
+    let (s, r) = bounded::<()>(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            assert!(r.recv().is_err());
+        });
+        scope.spawn(move |_| {
+            thread::sleep(ms(1000));
+            drop(s);
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn spsc() {
+    const COUNT: usize = 100_000;
+
+    let (s, r) = bounded(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            for i in 0..COUNT {
+                assert_eq!(r.recv(), Ok(i));
+            }
+            assert!(r.recv().is_err());
+        });
+        scope.spawn(move |_| {
+            for i in 0..COUNT {
+                s.send(i).unwrap();
+            }
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn mpmc() {
+    const COUNT: usize = 25_000;
+    const THREADS: usize = 4;
+
+    let (s, r) = bounded::<usize>(0);
+    let v = (0..COUNT).map(|_| AtomicUsize::new(0)).collect::<Vec<_>>();
+
+    scope(|scope| {
+        for _ in 0..THREADS {
+            scope.spawn(|_| {
+                for _ in 0..COUNT {
+                    let n = r.recv().unwrap();
+                    v[n].fetch_add(1, Ordering::SeqCst);
+                }
+            });
+        }
+        for _ in 0..THREADS {
+            scope.spawn(|_| {
+                for i in 0..COUNT {
+                    s.send(i).unwrap();
+                }
+            });
+        }
+    })
+    .unwrap();
+
+    for c in v {
+        assert_eq!(c.load(Ordering::SeqCst), THREADS);
+    }
+}
+
+#[test]
+fn stress_oneshot() {
+    const COUNT: usize = 10_000;
+
+    for _ in 0..COUNT {
+        let (s, r) = bounded(1);
+
+        scope(|scope| {
+            scope.spawn(|_| r.recv().unwrap());
+            scope.spawn(|_| s.send(0).unwrap());
+        })
+        .unwrap();
+    }
+}
+
+#[test]
+fn stress_iter() {
+    const COUNT: usize = 1000;
+
+    let (request_s, request_r) = bounded(0);
+    let (response_s, response_r) = bounded(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            let mut count = 0;
+            loop {
+                for x in response_r.try_iter() {
+                    count += x;
+                    if count == COUNT {
+                        return;
+                    }
+                }
+                let _ = request_s.try_send(());
+            }
+        });
+
+        for _ in request_r.iter() {
+            if response_s.send(1).is_err() {
+                break;
+            }
+        }
+    })
+    .unwrap();
+}
+
+#[test]
+fn stress_timeout_two_threads() {
+    const COUNT: usize = 100;
+
+    let (s, r) = bounded(0);
+
+    scope(|scope| {
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                if i % 2 == 0 {
+                    thread::sleep(ms(50));
+                }
+                loop {
+                    if let Ok(()) = s.send_timeout(i, ms(10)) {
+                        break;
+                    }
+                }
+            }
+        });
+
+        scope.spawn(|_| {
+            for i in 0..COUNT {
+                if i % 2 == 0 {
+                    thread::sleep(ms(50));
+                }
+                loop {
+                    if let Ok(x) = r.recv_timeout(ms(10)) {
+                        assert_eq!(x, i);
+                        break;
+                    }
+                }
+            }
+        });
+    })
+    .unwrap();
+}
+
+#[test]
+fn drops() {
+    static DROPS: AtomicUsize = AtomicUsize::new(0);
+
+    #[derive(Debug, PartialEq)]
+    struct DropCounter;
+
+    impl Drop for DropCounter {
+        fn drop(&mut self) {
+            DROPS.fetch_add(1, Ordering::SeqCst);
+        }
+    }
+
+    let mut rng = thread_rng();
+
+    for _ in 0..100 {
+        let steps = rng.gen_range(0..3_000);
+
+        DROPS.store(0, Ordering::SeqCst);
+        let (s, r) = bounded::<DropCounter>(0);
+
+        scope(|scope| {
+            scope.spawn(|_| {
+                for _ in 0..steps {
+                    r.recv().unwrap();
+                }
+            });
+
+            scope.spawn(|_| {
+                for _ in 0..steps {
+                    s.send(DropCounter).unwrap();
+                }
+            });
+        })
+        .unwrap();
+
+        assert_eq!(DROPS.load(Ordering::SeqCst), steps);
+        drop(s);
+        drop(r);
+        assert_eq!(DROPS.load(Ordering::SeqCst), steps);
+    }
+}
+
+// #[test]
+// fn fairness() {
+//     const COUNT: usize = 10_000;
+
+//     let (s1, r1) = bounded::<()>(0);
+//     let (s2, r2) = bounded::<()>(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             let mut hits = [0usize; 2];
+//             for _ in 0..COUNT {
+//                 select! {
+//                     recv(r1) -> _ => hits[0] += 1,
+//                     recv(r2) -> _ => hits[1] += 1,
+//                 }
+//             }
+//             assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+//         });
+
+//         let mut hits = [0usize; 2];
+//         for _ in 0..COUNT {
+//             select! {
+//                 send(s1, ()) -> _ => hits[0] += 1,
+//                 send(s2, ()) -> _ => hits[1] += 1,
+//             }
+//         }
+//         assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn fairness_duplicates() {
+//     const COUNT: usize = 10_000;
+
+//     let (s, r) = bounded::<()>(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             let mut hits = [0usize; 5];
+//             for _ in 0..COUNT {
+//                 select! {
+//                     recv(r) -> _ => hits[0] += 1,
+//                     recv(r) -> _ => hits[1] += 1,
+//                     recv(r) -> _ => hits[2] += 1,
+//                     recv(r) -> _ => hits[3] += 1,
+//                     recv(r) -> _ => hits[4] += 1,
+//                 }
+//             }
+//             assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+//         });
+
+//         let mut hits = [0usize; 5];
+//         for _ in 0..COUNT {
+//             select! {
+//                 send(s, ()) -> _ => hits[0] += 1,
+//                 send(s, ()) -> _ => hits[1] += 1,
+//                 send(s, ()) -> _ => hits[2] += 1,
+//                 send(s, ()) -> _ => hits[3] += 1,
+//                 send(s, ()) -> _ => hits[4] += 1,
+//             }
+//         }
+//         assert!(hits.iter().all(|x| *x >= COUNT / hits.len() / 2));
+//     })
+//     .unwrap();
+// }
+
+// #[test]
+// fn recv_in_send() {
+//     let (s, r) = bounded(0);
+
+//     scope(|scope| {
+//         scope.spawn(|_| {
+//             thread::sleep(ms(100));
+//             r.recv()
+//         });
+
+//         scope.spawn(|_| {
+//             thread::sleep(ms(500));
+//             s.send(()).unwrap();
+//         });
+
+//         select! {
+//             send(s, r.recv().unwrap()) -> _ => {}
+//         }
+//     })
+//     .unwrap();
+// }
+
+#[test]
+fn channel_through_channel() {
+    const COUNT: usize = 1000;
+
+    type T = Box<dyn Any + Send>;
+
+    let (s, r) = bounded::<T>(0);
+
+    scope(|scope| {
+        scope.spawn(move |_| {
+            let mut s = s;
+
+            for _ in 0..COUNT {
+                let (new_s, new_r) = bounded(0);
+                let new_r: T = Box::new(Some(new_r));
+
+                s.send(new_r).unwrap();
+                s = new_s;
+            }
+        });
+
+        scope.spawn(move |_| {
+            let mut r = r;
+
+            for _ in 0..COUNT {
+                r = r
+                    .recv()
+                    .unwrap()
+                    .downcast_mut::<Option<Receiver<T>>>()
+                    .unwrap()
+                    .take()
+                    .unwrap()
+            }
+        });
+    })
+    .unwrap();
+}