use crateWorld;
pub type SystemFn = fn;
/// The retained-UI pipeline systems, in run order. The frame's post-update
/// stage drives them through
/// [`run_retained_ui_schedule`](crate::plugins::ui::run_retained_ui_schedule),
/// right after transform propagation. Composing
/// [`UiPlugin`](crate::plugins::ui::UiPlugin) populates the list with
/// [`build_default_retained_ui_schedule`](crate::plugins::ui::build_default_retained_ui_schedule).