Well, the only suggestion I would have is to use,

```uniq => LJ::UniqCookie->current_uniq // 'undefined',```

That way it's always set to something at least. I don't know if that's better than dropping it from the hash if we don't have one, though. In theory the code is supposed to support turning off unique cookies. In practice, we never have them off so I don't know what would break if we did have them off.

Either fix is fine, I was just curious if it broke anything to have it undefined. I suspect it doesn't.