public long SetNX(string key, byte[] value)
{
if (key == null)
throw new ArgumentNullException("key");
value = value ?? TypeConstants.EmptyByteArray;
if (value.Length > OneGb)
throw new ArgumentException("value exceeds 1G", "value");
return SendExpectLong(Commands.SetNx, key.ToUtf8Bytes(), value);
}