public byte[][] HMGet(string hashId, params byte[][] keys)
{
if (hashId == null)
throw new ArgumentNullException("hashId");
if (keys.Length == 0)
throw new ArgumentNullException("keys");
var cmdArgs = MergeCommandWithArgs(Commands.HMGet, hashId.ToUtf8Bytes(), keys);
return SendExpectMultiData(cmdArgs);
}