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: main.rs
    path of file: ./repos/axum/examples/low-level-openssl/src
    
    the code of the file until where you have to start completion: use axum::{http::Request, routing::get, Router};
use futures_util::pin_mut;
use hyper::body::Incoming;
use hyper_util::rt::{TokioExecutor, TokioIo};
use openssl::ssl::{Ssl, SslAcceptor, SslFiletype, SslMethod};
use std::{path::PathBuf, pin::Pin};
use tokio::net::TcpListener;
use tokio_openssl::SslStream;
use tower::Service;
use tracing::{error, info, warn};
use tracing_subscriber::{layer::SubscriberExt, util::SubscriberInitExt};

#[tokio::main]
async fn main() {
    tracing_subscriber::registry()
        .with(
            tracing_subscriber::EnvFilter::try_from_default_env()
                .unwrap_or_else(|_| "example_low_level_openssl=debug".into()),
        )
        .with(tracing_subscriber::fmt::layer())
        .init();

    let mut tls_builder = SslAcceptor::mozilla_modern_v5(SslMethod::tls()).unwrap();

    tls_builder
        .set_certificate_file(
            PathBuf::from(env!("CARGO_MANIFEST_DIR"))
                .join("self_signed_certs")
                .join("cert.pem"),
            SslFiletype::PEM,
        )
        .unwrap();

    tls_builder
        .set_private_key_file(
            PathBuf::from(env!("CARGO_MANIFEST_DIR"))
                .join("self_signed_certs")
                .join("key.pem"),
            SslFiletype::PEM,
        )
        .unwrap();

    tls_builder.check_private_key().unwrap();

    let tls_acceptor = tls_builder.build();

    let bind = "[::1]:3000";
    let tcp_listener = TcpListener::bind(bind).await.unwrap();
    info!("HTTPS server listening on {bind}. To contact curl -k https://localhost:3000");
    let app = Router::new().route("/", get(handler));

    pin_mut!(tcp_listener);

    loop {
        let tower_service = app.clone();
        let tls_acceptor = tls_acceptor.clone();

        // Wait for new tcp connection
        let 
    
async fn main() {
    tracing_subscriber::registry()
        .with(
            tracing_subscriber::EnvFilter::try_from_default_env()
                .unwrap_or_else(|_| "example_low_level_openssl=debug".into()),
        )
        .with(tracing_subscriber::fmt::layer())
        .init();

    let mut tls_builder = SslAcceptor::mozilla_modern_v5(SslMethod::tls()).unwrap();

    tls_builder
        .set_certificate_file(
            PathBuf::from(env!("CARGO_MANIFEST_DIR"))
                .join("self_signed_certs")
                .join("cert.pem"),
            SslFiletype::PEM,
        )
        .unwrap();

    tls_builder
        .set_private_key_file(
            PathBuf::from(env!("CARGO_MANIFEST_DIR"))
                .join("self_signed_certs")
                .join("key.pem"),
            SslFiletype::PEM,
        )
        .unwrap();

    tls_builder.check_private_key().unwrap();

    let tls_acceptor = tls_builder.build();

    let bind = "[::1]:3000";
    let tcp_listener = TcpListener::bind(bind).await.unwrap();
    info!("HTTPS server listening on {bind}. To contact curl -k https://localhost:3000");
    let app = Router::new().route("/", get(handler));

    pin_mut!(tcp_listener);

    loop {
        let tower_service = app.clone();
        let tls_acceptor = tls_acceptor.clone();

        // Wait for new tcp connection
        let (cnx, addr) = tcp_listener.accept().await.unwrap();

        tokio::spawn(async move {
            let ssl = Ssl::new(tls_acceptor.context()).unwrap();
            let mut tls_stream = SslStream::new(ssl, cnx).unwrap();
            if let Err(err) = SslStream::accept(Pin::new(&mut tls_stream)).await {
                error!(
                    "error during tls handshake connection from {}: {}",
                    addr, err
                );
                return;
            }

            // Hyper has its own `AsyncRead` and `AsyncWrite` traits and doesn't use tokio.
            // `TokioIo` converts between them.
            let stream = TokioIo::new(tls_stream);

            // Hyper also has its own `Service` trait and doesn't use tower. We can use
            // `hyper::service::service_fn` to create a hyper `Service` that calls our app through
            // `tower::Service::call`.
            let hyper_service = hyper::service::service_fn(move |request: Request<Incoming>| {
                // We have to clone `tower_service` because hyper's `Service` uses `&self` whereas
                // tower's `Service` requires `&mut self`.
                //
                // We don't need to call `poll_ready` since `Router` is always ready.
                tower_service.clone().call(request)
            });

            let ret = hyper_util::server::conn::auto::Builder::new(TokioExecutor::new())
                .serve_connection_with_upgrades(stream, hyper_service)
                .await;

            if let Err(err) = ret {
                warn!("error serving connection from {}: {}", addr, err);
            }
        });
    }
}