def test_proxyMethod(self):
        """
        The class created from L{proxyForInterface} passes methods on an
        interface to the object which is passed to its constructor.
        """
        klass = proxyForInterface(IProxiedInterface)
        yayable = Yayable()
        proxy = klass(yayable)
        proxy.yay()
        self.assertEqual(proxy.yay(), 2)
        self.assertEqual(yayable.yays, 2)

        The class created from L{proxyForInterface} passes methods on an
        interface to the object which is passed to its constructor.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_components.py