private function getPlaceholders($navItemPageId, $placeholderVar, $prevId)
    {
        return (new Query())
            ->from('cms_nav_item_page_block_item t1')
            ->select(['t1.id', 't1.block_id', 't1.json_config_values', 't1.json_config_cfg_values', 't1.variation', 't2.class'])
            ->innerJoin('cms_block t2', 't2.id=t1.block_id')
            ->where(['nav_item_page_id' => $navItemPageId, 'placeholder_var' => $placeholderVar, 'prev_id' => $prevId, 'is_hidden' => 0])
            ->orderBy(['sort_index' => SORT_ASC])
            ->all();
    }