Function set_timeout 

pub fn set_timeout(delay_ms: i32, callback: impl Fn() + 'static) -> TimerHandle

Schedules a one-shot callback on the application UI queue.

Store the returned handle when cancellation is required. Recurring work must schedule its next timeout explicitly.

use fui::prelude::*;

let timer = set_timeout(250, || {
    // Mutate retained application state, then invalidate affected UI.
});
assert!(cancel_timeout(timer));