public long ZUnionStore(string intoSetId, params string[] setIds) { var setIdsList = new List<string>(setIds); setIdsList.Insert(0, setIds.Length.ToString()); setIdsList.Insert(0, intoSetId); var cmdWithArgs = MergeCommandWithArgs(Commands.ZUnionStore, setIdsList.ToArray()); return SendExpectLong(cmdWithArgs); }