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: tcp_client_stream.rs
    path of file: ./repos/phaser/phaser/vendor/trust-dns-proto/src/tcp
    
    the code of the file until where you have to start completion: // Copyright 2015-2016 Benjamin Fry <benjaminfry@me.com>
//
// Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
// http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
// http://opensource.org/licenses/MIT>, at your option. This file may not be
// copied, modified, or distributed excep
    
    fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
        let message = try_ready_stream!(self.tcp_stream.poll_next_unpin(cx));

        // this is busted if the tcp connection doesn't have a peer
        let peer = self.tcp_stream.peer_addr();
        if message.addr() != peer {
            // TODO: this should be an error, right?
            warn!("{} does not match name_server: {}", message.addr(), peer)
        }

        Poll::Ready(Some(Ok(message)))
    }