class Foo():
    def myiter(self):
        for val in [1, 2, 3]:
            yield val


class Bar(Foo):
    def __init__(self):
        self.me = 0
    def myiter(self):
        for val in super().myiter():
            self.me += 1
            if self.me >= 2:
                super().myiter().close()
                return
            yield val