@:optionaloptionalstencil:Null<Bool>
@:optionaloptionalpreserveDrawingBuffer:Null<Bool>
@:optionaloptionalpremultipliedAlpha:Null<Bool>
@:optionaloptionalpowerPreference:Null<PowerPreference>
@:optionaloptionalfailIfMajorPerformanceCaveat:Null<Bool>
@:optionaloptionaldepth:Null<Bool>
@:optionaloptionalantialias:Null<Bool>
@:optionaloptionalalpha:Null<Bool>