Function read_after_close

pub async fn read_after_close<A, B, S, E>(alice: A, bob: B)
where
    A: StreamMuxer<Substream = S, Error = E> + Unpin,
    B: StreamMuxer<Substream = S, Error = E> + Unpin,
    S: AsyncRead + AsyncWrite + Send + Unpin + 'static,
    E: Debug,

Verifies that we can “half-close” a substream.