'If an encoding unknown to the L{client.ContentDecoderAgent} is found,
the response is unchanged.'

def test_unsupportedEncoding(self):

    agent = client.ContentDecoderAgent(self.agent, [('decoder1', Decoder1), ('decoder2', Decoder2)])
    deferred = agent.request('GET', 'http://example.com/foo')
    (req, res) = self.protocol.requests.pop()
    headers = http_headers.Headers({'foo': ['bar'], 'content-encoding': ['fizz']})
    response = Response(('HTTP', 1, 1), 200, 'OK', headers, None)
    res.callback(response)
    return deferred.addCallback(self.assertIdentical, response)
