def test_responseFromMessageMaxSize(self):
        """
        L{server.DNSServerFactory._responseFromMessage} generates a response
        message whose C{maxSize} attribute has the same value as that found
        on the request.
        """
        factory = server.DNSServerFactory()
        request = dns.Message()
        request.maxSize = 0
        response = factory._responseFromMessage(message=request)

        self.assertEqual(request.maxSize, response.maxSize)

        L{server.DNSServerFactory._responseFromMessage} generates a response
        message whose C{maxSize} attribute has the same value as that found
        on the request.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/names/test/test_server.py