code: public boolean addAll(@NonNull final Collection<? extends T> collection) {
          boolean result = mItems.addAll(collection);
          notifyDataSetChanged();
          return result;
      }
docs: 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.
  
  @param collection the collection of objects.
  
  @return {@code true} if this {@code List} is modified, {@code false} otherwise.