public static IObservable <T> LastOr <T>(this IObservableList <T> self, T element)
{
return(self.ToObservableImmutableList().Select(list => list.LastOr(element)));
}
public static IObservable <Optional <T> > LastOrNone <T>(this IObservableList <T> self)
{
return(self.ToObservableImmutableList().Select(list => list.LastOrNone()));
}