private void FBPlayersFromIDs(List <string> fbIDs) { int counter = fbIDs.Count; UniRx.IObservable <string> left = fbIDs.ToObservable(); Subject <bool> queries = new Subject <bool>(); left.Zip(queries.StartWith(value : true), (string id, bool b) => id).Subscribe(delegate(string id) { PersistentSingleton <FacebookAPIService> .Instance.LoadFriendAPI(id, delegate(FBPlayer f) { m_fbEventsInternal.OnNext(UniRx.Tuple.Create(FacebookEvent.FRIEND_DATA, (object)f)); counter--; queries.OnNext(value: true); }); }).AddTo(SceneLoader.Instance); }