@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.CUSTOM)
    public final Observable<T> debounce(long timeout, TimeUnit unit, Scheduler scheduler) {
        ObjectHelper.requireNonNull(unit, "unit is null");
        ObjectHelper.requireNonNull(scheduler, "scheduler is null");
        return RxJavaPlugins.onAssembly(new ObservableDebounceTimed<T>(this, timeout, unit, scheduler));
    }