def test_startedConnecting(self):
        """
        L{policies.WrappingFactory.startedConnecting} calls
        C{startedConnecting} on the underlying factory.
        """
        result = []
        class Factory(object):
            def startedConnecting(self, connector):
                result.append(connector)

        wrapper = policies.WrappingFactory(Factory())
        connector = object()
        wrapper.startedConnecting(connector)
        self.assertEqual(result, [connector])

        L{policies.WrappingFactory.startedConnecting} calls
        C{startedConnecting} on the underlying factory.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_policies.py