Get a reference to data at self as a SDLMouseWheelEvent

Require: is_mouse_wheel

Property definitions

sdl2 $ SDLEventBuffer :: to_mouse_wheel
	# Get a reference to data at `self` as a `SDLMouseWheelEvent`
	#
	# Require: `is_mouse_wheel`
	fun to_mouse_wheel: SDLMouseWheelEvent `{ return self; `}
lib/sdl2/events.nit:94,2--97,58