Function schedule 

pub fn schedule<F, R>(fun: F)
where
    F: FnOnce(()) -> R + 'static,
    R: IntoResult<()>,
    <R as IntoResult<()>>::Error: Error + 'static,

Binding to vim.schedule().

Schedules a callback to be invoked soon by the main event-loop. Useful to avoid textlock or other temporary restrictions.