public function addFolder($folderName, $parentFolderId = 0)
    {
        $model = new StorageFolder();
        $model->name = $folderName;
        $model->parent_id = $parentFolderId;
        $model->timestamp_create = time();
        $this->deleteHasCache(self::CACHE_KEY_FOLDER);
        if ($model->save(false)) {
            return $model->id;
        }

        return false;
    }