def METHOD_NAME(self):
    class Foo(object):
        @PropertySub
        def spam(self):
            """a docstring"""
            return 1
        @spam.getter
        def spam(self):
            """a new docstring"""
            return 2
    self.assertEqual(Foo.spam.__doc__, "a new docstring")
    class FooBase(object):
        @PropertySub
        def spam(self):
            """a docstring"""
            return 1
    class Foo2(FooBase):
        @FooBase.spam.getter
        def spam(self):
            """a new docstring"""
            return 2
    self.assertEqual(Foo.spam.__doc__, "a new docstring")