pub type OnBeforeUnloadEventHandler<D> = Option<Rc<OnBeforeUnloadEventHandlerNonNull<D>>>;Aliased Type§
pub enum OnBeforeUnloadEventHandler<D> {
    None,
    Some(Rc<OnBeforeUnloadEventHandlerNonNull<D>>),
}pub type OnBeforeUnloadEventHandler<D> = Option<Rc<OnBeforeUnloadEventHandlerNonNull<D>>>;pub enum OnBeforeUnloadEventHandler<D> {
    None,
    Some(Rc<OnBeforeUnloadEventHandlerNonNull<D>>),
}