Function jobs 

pub(crate) async fn jobs<F, Fut>(
    name: &str,
    count: usize,
    concurrency: usize,
    token: &CancellationToken,
    execute: F,
) -> PhaseReport
where
    F: Fn(usize) -> Fut + Send + Sync + 'static,
    Fut: Future<Output = Outcome> + Send + 'static,