def test_cancelTimeoutNoTimeout(self):
        """
        Does nothing if no timeout is already set.
        """
        sut, clock = self.getProtocolAndClock()
        self.assertIsNone(sut.timeoutCall)

        sut.cancelTimeout()

        # Protocol is still connected.
        self.assertFalse(sut.wrappedProtocol.disconnected)

        Does nothing if no timeout is already set.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_policies.py