void OnNotificationCollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
        {
            // we only care about Adds
            if (e.Action != NotifyCollectionChangedAction.Add)
            {
                return;
            }

            // ... and then, only if we're auto-scrolling
            if (!AutoScroll)
            {
                return;
            }

            ItemCollection items = NotificationList.Items;

            NotificationList.ScrollIntoView(items[items.Count - 1]);
        }