def test_validCoerce(self):
        """
        Test the answers with valid input.
        """
        self.assertEqual(0, usage.portCoerce("0"))
        self.assertEqual(3210, usage.portCoerce("3210"))
        self.assertEqual(65535, usage.portCoerce("65535"))

        Test the answers with valid input.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_usage.py