class MultiInterval implements Multi<Long> {

    @Override
    public void subscribe(Flow.Subscriber<? super Long> subscriber) {
        IntervalSubscription subscription = new IntervalSubscription(subscriber);
        subscriber.onSubscribe(subscription);

        subscription.setFuture(executor.scheduleAtFixedRate(subscription, initialDelay, period, unit));
    }

      MultiInterval(long initialDelay, long period, TimeUnit unit, ScheduledExecutorService executor);

}