@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final <V> Observable<T> timeout(Function<? super T, ? extends ObservableSource<V>> itemTimeoutIndicator,
            ObservableSource<? extends T> other) {
        ObjectHelper.requireNonNull(other, "other is null");
        return timeout0(null, itemTimeoutIndicator, other);
    }