@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final Observable<T> sorted(Comparator<? super T> sortFunction) {
        ObjectHelper.requireNonNull(sortFunction, "sortFunction is null");
        return toList().toObservable().map(Functions.listSorter(sortFunction)).flatMapIterable(Functions.<List<T>>identity());
    }