docs: def get_slice(self, key, column_parent, predicate, consistency_level):
      """
      Get the group of columns contained by column_parent (either a ColumnFamily name or a ColumnFamily/SuperColumn name
      pair) specified by the given SlicePredicate. If no matching values are found, an empty list is returned.
  
      Parameters:
       - key
       - column_parent
       - predicate
       - consistency_level
      """
      self._seqid += 1
      d = self._reqs[self._seqid] = defer.Deferred()
      self.send_get_slice(key, column_parent, predicate, consistency_level)
      return d