def _find_one_after_last_labeled_index(self):
        body_index = 0
        while self.bodies[body_index].segment_id in self.state.body_labels:
            body_index += 1
        return body_index
def test_vice_versa(self):
        class First(Structure):
            pass
        class Second(Structure):
            pass

        First._fields_ = [("second", Second)]

        try:
            Second._fields_ = [("first", First)]
        except AttributeError as details:
            self.assertTrue("_fields_ is final" in
                            str(details))
        else:
            self.fail("AttributeError not raised")