docs: def update(self, identity_id, service, token=None):
          """ Update the token
  
              :param identity_id: The ID of the identity to retrieve
              :return: dict of REST API output with headers attached
              :rtype: :class:`~datasift.request.DictResponse`
              :raises: :class:`~datasift.exceptions.DataSiftApiException`,
                  :class:`requests.exceptions.HTTPError`
          """
  
          params = {}
  
          if token:
              params['token'] = token
  
          return self.request.put(str(identity_id) + '/token/' + service, params)