code: def fetch_next_block(self):
          
          if not self._has_more_pages():
              return []
          
          if len(self._buffer):
              # if there is anything in the buffer returns that
              res = list(self._buffer)
              self._buffer.clear()
              return res
          else:
              # fetches the next block
              return self._fetch_next_block()
docs: Returns a block of results with respecting retry policy.
          
          This method only exists for backward compatibility reasons. (Because QueryIterable
          has exposed fetch_next_block api).
          
          :return:
              List of results.
          :rtype: list