public void addItems(final int pos, final Collection<T> items) {
        final int insertedCount = addItemInternal(pos, items);
        if (notifyOnEvents) {
            this.notifyItemRangeInserted(pos, insertedCount);
        }
    }
Return only READONLY list to prevent unwanted modifications
main/src/main/java/cgeo/geocaching/ui/recyclerview/ManagedListAdapter.java