class SimpleEventSignal1<E, R>

new (type:E)

dispatch (result:R):Void

hasListener (cb:R ‑> Void):Bool

listen (cb:R ‑> Void):Void

observe (cb:Void ‑> Void):Void

once (cb:R ‑> Void):Void

unlisten (cb:R ‑> Void):Void

unobserve (cb:Void ‑> Void):Void