public Observable<Integer> getScrollObservable(RecyclerView recyclerView, boolean withPreload) {
        return Observable.create(publisher -> {
            final RecyclerView.OnScrollListener listener = new RecyclerView.OnScrollListener() {

                private int lastVisibleItem;
                private int totalItemCount;

                @Override
                public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
                    super.onScrollStateChanged(recyclerView, newState);
                }

                @Override
                public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
                    super.onScrolled(recyclerView, dx, dy);

                    if (dy > 0) {
                        final LinearLayoutManager layoutManager = (LinearLayoutManager) recyclerView.getLayoutManager();

                        totalItemCount = layoutManager.getItemCount();
                        lastVisibleItem = layoutManager.findLastVisibleItemPosition();

                        if (!mIsLoading) {
                            if ((lastVisibleItem > totalItemCount - 5) && mLastVisibleItem < totalItemCount) {
                                mIsLoading = true;
                                mLastVisibleItem = totalItemCount;
                                publisher.onNext(totalItemCount);
                            }
                        }
                    }
                }
            };

            if (withPreload) {
                publisher.onNext(0);
            }

            recyclerView.addOnScrollListener(listener);
            publisher.setCancellable(() -> recyclerView.removeOnScrollListener(listener));
        });
    }