code: public Observable<SwipeEvent> observe() {
      this.swipeListener = createReactiveSwipeListener();
      return Observable.create(new ObservableOnSubscribe<SwipeEvent>() {
        @Override public void subscribe(ObservableEmitter<SwipeEvent> emitter) throws Exception {
          Swipe.this.emitter = emitter;
        }
      });
    }
docs: Observes swipe events with RxJava Observable.
  Remember to call {@link #dispatchTouchEvent(MotionEvent) dispatchTouchEvent} method as well.
  
  @return Observable<SwipeEvent> observable with stream of swipe events