Add a single listener to a game object's set of associated listeners. Any listeners that have previously been added or set via AddListener or SetListeners will remain as listeners and in_listenerGameObj will be added as an additional listener. Calling this function will override the default set of listeners and in_emitterGameObj will now reference its own, unique set of listeners.
- See also
||Emitter game object. Must have been previously registered via RegisterGameObj.
||Listener game object IDs that will be activated for in_emitterGameObj.