@BackpressureSupport(BackpressureKind.PASS_THROUGH)
    @SchedulerSupport(SchedulerSupport.NONE)
    public final void safeSubscribe(Subscriber<? super T> s) {
        ObjectHelper.requireNonNull(s, "s is null");
        if (s instanceof SafeSubscriber) {
            subscribe((SafeSubscriber<? super T>)s);
        } else {
            subscribe(new SafeSubscriber<T>(s));
        }
    }