Test Of Interface Classes as parameters in functions

PlaneHandler.Constructor:
PassengerAiroPlane.Constructor:
CargoAiroPlane.Constructor:

PlaneHandler.levelPlane:
PassengerAiroPlane.setStickPosition:
PassengerAiroPlane.setThrustPosition:
PassengerAiroPlane.setAltimeter:

PlaneHandler.levelPlane:
CargoAiroPlane.setStickPosition:
CargoAiroPlane.setThrustPosition:
Can't find the fucking Altimeter.