Getter for query parameters for the next request.

        Returns:
            dict: A dictionary of query parameters.

def _get_query_params(self):
        """Getter for query parameters for the next request.

        Returns:
            dict: A dictionary of query parameters.
        """
        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