Function dispatch 

pub async fn dispatch<H, R, S, D>(
    host: &mut H,
    plan: &mut Plan,
    services: &Services<R, S>,
    catalog: &DefinitionCatalog,
    deadline: D,
) -> ExitCategory
where
    H: Host,
    R: JobRepository,
    S: ExplorerRepository,
    D: Future<Output = ()>,

Runs one command against the portable services.

The supplied deadline future completes when the client deadline elapses. Passing a future that never completes disables the deadline; the process entry point supplies a timer.