code: public static <T> org.reactivestreams.Subscriber<T> toSubscriber(final rx.Subscriber<T> rxSubscriber) {
          return new SubscriberAdapter<T>(rxSubscriber);
      }
docs: Convert an RxJava {@link rx.Subscriber} into a Reactive Streams {@link org.reactivestreams.Subscriber}.
  
  @param <T> the value type
  @param rxSubscriber an RxJava subscriber
  @return a Reactive Streams subscriber