def test_specifiedPeerAddress(self):
        """
        If a peer address is passed to L{StringTransport.__init__}, that
        value is returned from L{StringTransport.getPeer}.
        """
        address = object()
        self.assertIs(
            StringTransport(peerAddress=address).getPeer(), address)

        If a peer address is passed to L{StringTransport.__init__}, that
        value is returned from L{StringTransport.getPeer}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/internet/test/test_testing.py