Function make_looper 

pub fn make_looper<Fut1, Fut2>(
    token: CancellationToken,
    schedule: Schedule,
    stop_check_duration: Duration,
    task_function: impl Fn(DateTime<Utc>) -> Fut1 + Send + Sync + 'static,
    stop_function: impl Fn() -> Fut2 + Send + Sync + 'static,
) -> JoinHandle<()>
where
    Fut1: Future<Output = LoopState> + Send,
    Fut2: Future<Output = ()> + Send,