def test_failIfIdenticalPositive(self):
        """
        C{failIfIdentical} returns its first argument if its first and second
        arguments are not the same object.
        """
        x = object()
        y = object()
        result = self.failIfIdentical(x, y)
        self.assertEqual(x, result)

        C{failIfIdentical} returns its first argument if its first and second
        arguments are not the same object.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/trial/test/test_assertions.py