docs: def pause(self, historics_id, reason=""):
          """ Pause an existing Historics query.
  
              Uses API documented at http://dev.datasift.com/docs/api/rest-api/endpoints/historicspause
  
              :param historics_id: id of the job to pause
              :type historics_id: str
              :param reason: optional reason for pausing it
              :type reason: str
              :return: dict of REST API output with headers attached
              :rtype: :class:`~datasift.request.DictResponse`
              :raises: :class:`~datasift.exceptions.DataSiftApiException`, :class:`requests.exceptions.HTTPError`
          """
          params = {"id": historics_id}
          if reason != "":
              params["reason"] = reason
          return self.request.post('pause', data=params)