def test_writeSequenceForChannels(self):
        """
        L{H2Stream} objects can send a series of frames via C{writeSequence}.
        """
        connection = H2Connection()
        connection.requestFactory = DelayedHTTPHandlerProxy
        _, transport = self.connectAndReceive(
            connection, self.getRequestHeaders, []
        )

        stream = connection.streams[1]
        request = stream._request.original

        request.setResponseCode(200)
        stream.writeSequence([b'Hello', b',', b'world!'])
        request.finish()

        completionDeferred = connection._streamCleanupCallbacks[1]

        def validate(streamID):
            frames = framesFromBytes(transport.value())

            # Check that the stream is correctly terminated.
            self.assertTrue('END_STREAM' in frames[-1].flags)

            # Grab the data from the frames.
            dataChunks = [
                f.data for f in frames
                if isinstance(f, hyperframe.frame.DataFrame)
            ]
            self.assertEqual(
                dataChunks,
                [
                    b"Hello", b",", b"world!", b""
                ]
            )

        return completionDeferred.addCallback(validate)

        L{H2Stream} objects can send a series of frames via C{writeSequence}.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_http2.py