Function panorama_imap::client::inner::listen

async fn listen<C>(
    conn: ReadHalf<C>, 
    cmd_rx: UnboundedReceiver<(String, Command, UnboundedSender<Response>)>, 
    write_tx: UnboundedSender<String>, 
    greeting_tx: Sender<()>, 
    exit_rx: Receiver<()>
) -> Result<ReadHalf<C>> where
    C: AsyncRead + Unpin,