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/rust-bible/part5/axum-demo/src
    
    the code of the file until where you have to start completion: use async_trait::async_trait;
use axum::{
    extract::{Form, FromRequest, RequestParts},
    handler::Handler,
    http::Method,
    http::StatusCode,
    http::Uri,
    response::{Html, IntoResponse, Response},
    routing::{get, post},
    BoxError, Json, Router,
};
use serde::de::DeserializeOwned;
use serde::{Deseriali
    
async fn shutdown() {
    let ctrl_c = async {
        signal::ctrl_c()
            .await
            .expect("failed to install ctrl+c handler");
    };
    #[cfg(unix)]
    let terminate = async {
        signal::unix::signal(signal::unix::SignalKind::terminate())
            .expect("failed to install signal handler")
            .recv()
            .await;
    };

    #[cfg(not(unix))]
    let terminate = std::future::pending::<()>();

    tokio::select! {
        _ = ctrl_c => { // 按住ctrl +c 退出
            println!("server will shutdown")
        },
        _= terminate => {
            println!("received terminate signal")
        },
    }

    println!("signal received,starting graceful shutdown")
}