code: def parse_content_encoding(self, response_headers, response_data):
          
          if response_headers['content-encoding'] == 'gzip':
              buf = StringIO.StringIO(response_data)
              zipbuf = gzip.GzipFile(fileobj=buf)
              response_data = zipbuf.read()
          elif response_headers['content-encoding'] == 'deflate':
              data = StringIO.StringIO(zlib.decompress(response_data))
              response_data = data.read()
          else:
              raise errors.TestError(
                  'Received unknown Content-Encoding',
                  {
                      'content-encoding':
                          str(response_headers['content-encoding']),
                      'function': 'http.HttpResponse.parse_content_encoding'
                  })
          return response_data
docs: Parses a response that contains Content-Encoding to retrieve
          response_data