def test_multipleContentLengthHeaders(self):
        """
        If a response includes multiple I{Content-Length} headers,
        L{HTTPClientParser.dataReceived} raises L{ValueError} to indicate that
        the response is invalid and the transport is now unusable.
        """
        protocol = HTTPClientParser(
            Request(b'GET', b'/', _boringHeaders, None),
            None)

        protocol.makeConnection(StringTransport())
        self.assertRaises(
            ValueError,
            protocol.dataReceived,
            b'HTTP/1.1 200 OK\r\n'
            b'Content-Length: 1\r\n'
            b'Content-Length: 2\r\n'
            b'\r\n')

        If a response includes multiple I{Content-Length} headers,
        L{HTTPClientParser.dataReceived} raises L{ValueError} to indicate that
        the response is invalid and the transport is now unusable.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/test_newclient.py