new ()
read onlycomplete:Bool
onComplete:_Event_Void_Void<Void ‑> Void> = new Event<Void>()
onProgress:_Event_Int_Int_Void<Int ‑> Int ‑> Void> = new Event<Int -> Int>()
addLibrary (library:AssetLibrary):Void
addLibraryName (name:String):Void
load ():Void