How to use the testslide.lib._validate_return_type function in TestSlide

def assert_fails(self, value):
        assert_regex = (
            r"(?s)type of return must be .+; got .+ instead: .+Defined at .+:\d+"
        )
        with self.assertRaisesRegex(testslide.lib.TypeCheckError, assert_regex):
            testslide.lib._validate_return_type(
                self.callable_template, value, self.caller_frame_info
            )

def fails_for_valid_forward_reference_but_bad_type_passed(self):
        with self.assertRaisesRegex(
            testslide.lib.TypeCheckError,
            "type of return must be one of .*; got int instead:",
        ):
            testslide.lib._validate_return_type(
                Foo.get_maybe_foo, 33, self.caller_frame_info
            )

def passes_for_valid_forward_reference(self):
        testslide.lib._validate_return_type(
            Foo.get_maybe_foo, Foo(), self.caller_frame_info
        )