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: lib.rs
    path of file: ./repos/salvo/crates/flash/src
    
    the code of the file until where you have to start completion: //! The flash message lib for Savlo web server framework.
//!
//! Read more: <https://salvo.rs>
#![doc(html_favicon_url = "https://salvo.rs/favicon-32x32.png")]
#![doc(html_logo_url = "https://salvo.rs/images/logo.svg")]
#![cfg_attr(docsrs, feature(doc_cfg))]

use std::fmt::{self, Debug, Display, Formatter};
use std::future::Future;
use std::ops::Deref;

use salvo_core::{async_trait, Depot, FlowCtrl, Handler, Request, Response};
use serde::{Deserialize, Serialize};

#[macro_use]
mod cfg;

cfg_feature! {
    #![feature = "cookie-store"]

    mod cookie_store;
    pub use cookie_store::CookieStore;

    /// Helper function to create a `CookieStore`.
    pub fn cookie_store() -> CookieStore {
        CookieStore::new()
    }
}

cfg_feature! {
    #![feature = "session-store"]

    mod session_store;
    pub use session_store::SessionStore;

    /// Helper function to create a `SessionStore`.
    pub fn session_store() -> SessionStore {
    
    
    async fn test_session_store() {
        let session_handler = salvo_session::SessionHandler::builder(
            salvo_session::MemoryStore::new(),
            b"secretabsecretabsecretabsecretabsecretabsecretabsecretabsecretab",
        )
        .build()
        .unwrap();

        let session_name = "my-custom-session-name".to_string();
        let router = Router::new()
            .hoop(session_handler)
            .hoop(SessionStore::new().name(&session_name).into_handler())
            .push(Router::with_path("get").get(get_flash))
            .push(Router::with_path("set").get(set_flash));
        let service = Service::new(router);

        let respone = TestClient::get("http://127.0.0.1:5800/set").send(&service).await;
        assert_eq!(respone.status_code, Some(StatusCode::SEE_OTHER));

        let cookie = respone.headers().get(SET_COOKIE).unwrap();

        let mut respone = TestClient::get("http://127.0.0.1:5800/get")
            .add_header(COOKIE, cookie, true)
            .send(&service)
            .await;
        assert!(respone.take_string().await.unwrap().contains("Hey there!"));

        let mut respone = TestClient::get("http://127.0.0.1:5800/get")
            .add_header(COOKIE, cookie, true)
            .send(&service)
            .await;
        assert!(respone.take_string().await.unwrap().is_empty());
    }