def test_buildProtocolClient(self):
        """
        L{ClientFactory.buildProtocol} should be invoked with the address of
        the server to which a connection has been established, which should
        be the same as the address reported by the C{getHost} method of the
        transport of the server protocol and as the C{getPeer} method of the
        transport of the client protocol.
        """
        serverHost = self.server.protocol.transport.getHost()
        clientPeer = self.client.protocol.transport.getPeer()

        self.assertEqual(
            self.clientWrapper.addresses,
            [IPv4Address('TCP', serverHost.host, serverHost.port)])
        self.assertEqual(
            self.clientWrapper.addresses,
            [IPv4Address('TCP', clientPeer.host, clientPeer.port)])

        L{ClientFactory.buildProtocol} should be invoked with the address of
        the server to which a connection has been established, which should
        be the same as the address reported by the C{getHost} method of the
        transport of the server protocol and as the C{getPeer} method of the
        transport of the client protocol.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/test/test_tcp.py