def test_stopTryingWhenConnected(self):
        """
        If a L{ReconnectingClientFactory} has C{stopTrying} called while it is
        connected, it does not subsequently attempt to reconnect if the
        connection is later lost.
        """
        class NoConnectConnector(object):
            def stopConnecting(self):
                raise RuntimeError("Shouldn't be called, we're connected.")
            def connect(self):
                raise RuntimeError("Shouldn't be reconnecting.")

        c = ReconnectingClientFactory()
        c.protocol = Protocol
        # Let's pretend we've connected:
        c.buildProtocol(None)
        # Now we stop trying, then disconnect:
        c.stopTrying()
        c.clientConnectionLost(NoConnectConnector(), None)
        self.assertFalse(c.continueTrying)

        If a L{ReconnectingClientFactory} has C{stopTrying} called while it is
        connected, it does not subsequently attempt to reconnect if the
        connection is later lost.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_factories.py