docs: def get_range_slices(self, column_parent, predicate, range, consistency_level):
      """
      returns a subset of columns for a contiguous range of keys.
  
      Parameters:
       - column_parent
       - predicate
       - range
       - consistency_level
      """
      self._seqid += 1
      d = self._reqs[self._seqid] = defer.Deferred()
      self.send_get_range_slices(column_parent, predicate, range, consistency_level)
      return d