Gzipped Response with web.client.Agent

Hello,

I've putted together examples from the web (see below) to replace getPage with web.client.Agent and it works fine. Now, I'd like to get gzipped response, but I can't get gunzipping to work before returning result. 

Thanks for help!

class StringGzipReceiver(Protocol):
    def __init__(self):
        self.string = None
        self.deferred = defer.Deferred()

    def dataReceived(self, bytes):
        print "dataReceived"
        print type(bytes)
        if self.string:
            self.string += bytes
        else:
            self.string = bytes

    def connectionLost(self, reason):
        if reason.check(ResponseDone) or reason.check(PotentialDataLoss):
            gzipper = gzip.GzipFile(fileobj=self.string)
            gz = gzipper.read()
            result = unicode(gz, 'UTF-8')
            self.deferred.callback(result)
        else:
            self.deferred.errback(reason)


class StringReceiver(Protocol):
    def __init__(self):
        self.string_io = codecs.getwriter('utf_8')(StringIO())
        self.deferred = defer.Deferred()

    def dataReceived(self, bytes):
        self.string_io.write(bytes)

    def connectionLost(self, reason):
        if reason.check(ResponseDone) or reason.check(PotentialDataLoss):
            self.deferred.callback(self.string_io.getvalue())
        else:
            self.deferred.errback(reason)


class StringProducer(object):
    implements(IBodyProducer)

    def __init__(self, body):
        self.body = body
        self.length = len(body)

    def startProducing(self, consumer):
        consumer.write(self.body)
        return succeed(None)

    def pauseProducing(self):
        pass

    def stopProducing(self):
        pass







def SearchHotelsByID():
    host = 'demo.com'
    postdata = 'some data'   
    headers = {
        'Host'              : [host],
        'Accept-Encoding'   : ['gzip']
        }

    def cbRequest(response):
        stringReceiver = StringGzipReceiver()
        response.deliverBody(stringReceiver)
        return stringReceiver.deferred

    def _noPage(failure):
        print "Error: %s" % failure.getErrorMessage()
        print failure.getTraceback()
        return failure

    agent = Agent(reactor)
    d = agent.request(
        'POST',
        url,
        headers=Headers(headers),
        bodyProducer=StringProducer(postdata)
        )
    d.addCallback(cbRequest)
    d.addErrback(_noPage)
    d.addBoth(finish)

    return d