code: public void notifyAdapterItemRangeInserted(int position, int itemCount) {
          // handle our extensions
          for (IAdapterExtension<Item> ext : mExtensions.values()) {
              ext.notifyAdapterItemRangeInserted(position, itemCount);
          }
          cacheSizes();
          notifyItemRangeInserted(position, itemCount);
      }
docs: wraps notifyItemRangeInserted
  
  @param position  the global position
  @param itemCount the count of items inserted