code: def _get_query_params(self):
          
          result = {}
          if self.next_page_token is not None:
              result[self._PAGE_TOKEN] = self.next_page_token
          if self.max_results is not None:
              result[self._MAX_RESULTS] = self.max_results - self.num_results
          result.update(self.extra_params)
          return result
docs: Getter for query parameters for the next request.
  
          Returns:
              dict: A dictionary of query parameters.