public boolean addAll(@NonNull final Collection<? extends T> collection){
  boolean result=mItems.addAll(collection);
  notifyDataSetChanged();
  return result;
}

public boolean addAll ( @ NonNull final Collection < ? extends T > collection ) { boolean result = mItems . addAll ( collection ) ; notifyDataSetChanged ( ) ; return result ; }
adds the objects in the specified collection to the end of this list . the objects are added in the order in which they are returned from the collection ' s iterator .
