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: gateway.rs
    path of file: ./repos/hyper/examples
    
    the code of the file until where you have to start completion: #![deny(warnings)]

use hyper::{server::conn::http1, service::service_fn};
use std::net::SocketAddr;
use tokio::net::{TcpListener, TcpStream};

#[path = "../benches/support/mod.rs"]
mod support;
use support::TokioIo;

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    pretty_env_logger::init();

    let in_addr: SocketAddr = ([127, 0, 0, 1], 3001).into();
    let out_addr: SocketAddr = ([127, 0, 0, 1], 3000).into();

    let out_addr_clone = out_addr.clone();

    let listener = TcpListener::bind(in_addr).await?;

    println!("Listening on http://{}", in_addr);
    println!("Proxying on http://{}", out_addr);

    loop {
        let (stream, _) = listener.accept().await?;
        let io = TokioIo::new(stream);

        // This is the `Service` that will handle the connection.
        // `service_fn` is a helper to convert a function that
        // returns a Response into a `Service`.
        let service = service_fn(move |mut req| {
            let uri_string = format!(
                "http://{}{}",
                out_addr_clone,
                req.uri()
                    .path_and_query()
                    .map(|x| x.as_str())
                    .unwrap_or("/")
            );
            let uri = uri_string.parse().unwrap();
            *req.uri_mut() = uri;

            let host = req.uri().host().expect("uri has no host");
            let port = req.uri().port_u16().unwrap_or(80);
            let addr = format!("{}:{}", host, port);

            async move {
                let client_stream = TcpStream::connect(addr).await.unwrap();
            
    
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    pretty_env_logger::init();

    let in_addr: SocketAddr = ([127, 0, 0, 1], 3001).into();
    let out_addr: SocketAddr = ([127, 0, 0, 1], 3000).into();

    let out_addr_clone = out_addr.clone();

    let listener = TcpListener::bind(in_addr).await?;

    println!("Listening on http://{}", in_addr);
    println!("Proxying on http://{}", out_addr);

    loop {
        let (stream, _) = listener.accept().await?;
        let io = TokioIo::new(stream);

        // This is the `Service` that will handle the connection.
        // `service_fn` is a helper to convert a function that
        // returns a Response into a `Service`.
        let service = service_fn(move |mut req| {
            let uri_string = format!(
                "http://{}{}",
                out_addr_clone,
                req.uri()
                    .path_and_query()
                    .map(|x| x.as_str())
                    .unwrap_or("/")
            );
            let uri = uri_string.parse().unwrap();
            *req.uri_mut() = uri;

            let host = req.uri().host().expect("uri has no host");
            let port = req.uri().port_u16().unwrap_or(80);
            let addr = format!("{}:{}", host, port);

            async move {
                let client_stream = TcpStream::connect(addr).await.unwrap();
                let io = TokioIo::new(client_stream);

                let (mut sender, conn) = hyper::client::conn::http1::handshake(io).await?;
                tokio::task::spawn(async move {
                    if let Err(err) = conn.await {
                        println!("Connection failed: {:?}", err);
                    }
                });

                sender.send_request(req).await
            }
        });

        tokio::task::spawn(async move {
            if let Err(err) = http1::Builder::new().serve_connection(io, service).await {
                println!("Failed to serve the connection: {:?}", err);
            }
        });
    }
}