Right, looks a bit like a matter of taste functional vs. OO.
If the keyring for example accepts keyid in hex then a bit syntactic sugar looks nice to me:
```
var keyIds = key.getKeyIds();
// think I understand now your previous comment, you want keyIds to be e.g. of class `keyidlist`?
// would need to map this
keyIds.map(function(keyid) { return keyid.toHex() }
keyring.getPacketlistsForKeyIds(keyIds)
```
vs.
```
keyring.getPacketlistsForKeyIds(key.getKeyIdsHex());
```