code: def exists(self, client=None):
          
          client = self._require_client(client)
          try:
              response = client.connection.api_request(method='GET', path=self.path)
          except NotFound:
              return False
          else:
              # projectname gets prefixed, this retrieves correct path with prefixed project name
              # see https://code.google.com/p/googleappengine/issues/detail?id=10199
              if os.path.split(response.get("id"))[-1] == self.id:
                  self.full_name = response.get("id")
                  return True
              else:
                  return False
docs: API call:  test for the existence of the taskqueue via a GET request
  
          See
          https://cloud.google.com/appengine/docs/python/taskqueue/rest/taskqueues/get
  
          :type client: :class:`taskqueue.client.Client` or ``NoneType``
          :param client: the client to use.  If not passed, falls back to the
                         ``client`` stored on the current taskqueue.