public function findTreeEntities(QueryInterface $query, array $options) : QueryInterface
    {
        $query = $query->where(['dblist_id' => $options['listId']])
            ->order(['lft' => 'asc']);

        // workaround for getting spacer.
        $tree = $this->find('treeList', ['spacer' => '&nbsp;&nbsp;&nbsp;&nbsp;'])
                ->toArray();

        foreach ($query->all() as $item) {
            $id = $item->get('id');
            if (in_array($id, array_keys($tree))) {
                $item->set('spacer', $tree[$id]);
            }
        }

        return $query;
    }