code: public void diffUpdate(List<T> newList) {
      if (getCollection().size() == 0) {
        addAll(newList);
        notifyDataSetChanged();
      } else {
        DiffCallback diffCallback = new DiffCallback(collection, newList);
        DiffUtil.DiffResult diffResult = DiffUtil.calculateDiff(diffCallback);
        clear();
        addAll(newList);
        diffResult.dispatchUpdatesTo(this);
      }
    }
docs: Provides a ready to use diff update for our adapter based on the implementation of the
  standard equals method from Object.
  
  @param newList to refresh our content