public void Start()
        {
            _collectionChangedObservable = Observable.FromEventPattern<NotifyCollectionChangedEventHandler, NotifyCollectionChangedEventArgs>(x => Queue.CollectionChanged += x, x => Queue.CollectionChanged -= x);
            _observer = _collectionChangedObservable.DistinctUntilChanged().Where(x => x.EventArgs.Action == NotifyCollectionChangedAction.Add).ObserveOn(Scheduler.ThreadPool).Subscribe(x => ProcessItems());
        }