class MultiConcatArray implements Multi<T> {

    @Override
    public void subscribe(Flow.Subscriber<? super T> subscriber) {
        ConcatArraySubscriber<T> parent = new ConcatArraySubscriber<>(subscriber, sources);
        subscriber.onSubscribe(parent);
        parent.nextSource();
    }

      MultiConcatArray(Flow.Publisher<T>[] sources);

}