/// <summary>
/// Creates observable sequence from <paramref name="source"/> ListChanged events and selects the current snapshot of the list (<see cref="NotifyListChangedEventArgs{T}.Items"/>).
/// </summary>
public static IObservable <IList <T> > AsItemsBehaviorObservable <T>(this INotifyListChanged <T> source)
{
return(source.AsBehaviorObservable().Select(e => e.Items));
}