You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: stream_futures_ordered.rs
    path of file: ./repos/phaser/phaser/vendor/futures/tests
    
    the code of the file until where you have to start completion: use futures::channel::oneshot;
use futures::executor::{block_on, block_on_stream};
use futures::future::{self, join, Future, FutureExt, TryFutureExt};
use futures::stream::{FuturesOrdered, StreamExt};
use futures_test::task::noop_context;
use std::any::Any;

#[test]
fn works_1() {
    let (a_tx, a_rx) = oneshot::channel::<i32>();
    let (b_tx, b_rx) = oneshot::channel::<i32>()
    
fn queue_never_unblocked() {
    let (_a_tx, a_rx) = oneshot::channel::<Box<dyn Any + Send>>();
    let (b_tx, b_rx) = oneshot::channel::<Box<dyn Any + Send>>();
    let (c_tx, c_rx) = oneshot::channel::<Box<dyn Any + Send>>();

    let mut stream = vec![
        Box::new(a_rx) as Box<dyn Future<Output = _> + Unpin>,
        Box::new(
            future::try_select(b_rx, c_rx)
                .map_err(|e| e.factor_first().0)
                .and_then(|e| future::ok(Box::new(e) as Box<dyn Any + Send>)),
        ) as _,
    ]
    .into_iter()
    .collect::<FuturesOrdered<_>>();

    let cx = &mut noop_context();
    for _ in 0..10 {
        assert!(stream.poll_next_unpin(cx).is_pending());
    }

    b_tx.send(Box::new(())).unwrap();
    assert!(stream.poll_next_unpin(cx).is_pending());
    c_tx.send(Box::new(())).unwrap();
    assert!(stream.poll_next_unpin(cx).is_pending());
    assert!(stream.poll_next_unpin(cx).is_pending());
}