public void setOnRecyclerViewScrollListener(
     RecyclerView recyclerView,
     OnRecyclerViewScrollLocationListener onRecyclerViewScrollLocationListener) {
   ensureRecyclerViewScrollManager();
   recyclerViewScrollManager.setOnRecyclerViewScrollLocationListener(
       onRecyclerViewScrollLocationListener);
   recyclerViewScrollManager.setOnScrollManagerLocation(this);
   recyclerViewScrollManager.registerScrollListener(recyclerView);
 }
 public boolean isScrolling() {
   if (null != recyclerViewScrollManager) {
     return recyclerViewScrollManager.isScrolling();
   }
   return false;
 }