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: connection_tests.rs
    path of file: ./repos/sea-orm/tests
    
    the code of the file until where you have to start completion: pub mod common;

pub use common::{bakery_chain::*, setup::*, TestContext};
use pretty_assertions::assert_eq;
use sea_orm::prelude::*;

#[sea_orm_macros::test]
pub async fn connection_ping() {
    let ctx = TestContext::new("connection_ping").await;

    ctx.db.ping().await.unwrap();

    ctx.delete().await;
}

#[sea_orm_macros::test]
#[cfg(feature = "sqlx-mysql")]
pub async fn connection_ping_closed_mysql() {
    let ctx = std::rc::Rc::new(Box::new(TestContext::new("connection_ping_closed").await));
    let ctx_ping = std::rc::Rc::clone(&ctx);

    ctx.db.get_mysql_connection_pool().close().await;
    assert_eq!(
        ctx_p
    
pub async fn connection_ping_closed_sqlite() {
    let ctx = std::rc::Rc::new(Box::new(TestContext::new("connection_ping_closed").await));
    let ctx_ping = std::rc::Rc::clone(&ctx);

    ctx.db.get_sqlite_connection_pool().close().await;
    assert_eq!(
        ctx_ping.db.ping().await,
        Err(DbErr::ConnectionAcquire(ConnAcquireErr::ConnectionClosed))
    );

    let base_url = std::env::var("DATABASE_URL").unwrap();
    let mut opt = sea_orm::ConnectOptions::new(base_url);
    opt
        // The connection pool has a single connection only
        .max_connections(1)
        // A controlled connection acquire timeout
        .acquire_timeout(std::time::Duration::from_secs(2));

    let db = sea_orm::Database::connect(opt).await.unwrap();

    async fn transaction_blocked(db: &DatabaseConnection) {
        let _txn = sea_orm::TransactionTrait::begin(db).await.unwrap();
        // Occupy the only connection, thus forcing others fail to acquire connection
        tokio::time::sleep(std::time::Duration::from_secs(3)).await;
    }

    async fn transaction(db: &DatabaseConnection) {
        // Should fail to acquire
        let txn = sea_orm::TransactionTrait::begin(db).await;
        assert_eq!(
            txn.expect_err("should be a time out"),
            crate::DbErr::ConnectionAcquire(ConnAcquireErr::Timeout)
        )
    }

    tokio::join!(transaction_blocked(&db), transaction(&db));

    ctx.delete().await;
}