from functools import total_ordering


class C:
    def __lt__(self, other):
        return NotImplemented
    
    def __eq__(self, other):
        return self is other

@total_ordering
class D(C):
    pass


if __name__ == '__main__':
    a, b = C(), C()
    c, d = D(), D()
    try:
        a < b
    except TypeError:
        print("raised TypeError as expected")
    try:
        c < d
    except TypeError:
        print("raised TypeError as expected")