interface IOne

	get one as int


interface ITwo

	get two as int


class A implements IOne

	get one as int
		return 1


class B implements IOne, ITwo

	get one as int
		return 1

	get two as int
		return 2


class P

	def main
		ones = List<of IOne>()
		ones.add(A())
		ones.add(B())
		count = 0
		for one in ones
			if one implements ITwo  # former false warning: The expression (of type "IOne") is never of type "ITwo".
				count += 1
		assert count == 1  # if the false warning were correct, this assertion would fail at run-time, but it does not