public function getFoldersArray()
    {
        if ($this->_foldersArray === null) {
            $query = (new Query())
                ->from('{{%admin_storage_folder}} as folder')
                ->select(['folder.id', 'name', 'parent_id', 'timestamp_create', 'COUNT(file.id) filesCount'])
                ->where(['folder.is_deleted' => false])
                ->orderBy(['name' => 'ASC'])
                ->leftJoin('{{%admin_storage_file}} as file', 'folder.id=file.folder_id AND file.is_deleted = 0')
                ->groupBy(['folder.id'])
                ->indexBy(['id']);

            $this->_foldersArray = $this->getQueryCacheHelper($query, self::CACHE_KEY_FOLDER);
        }

        return $this->_foldersArray;
    }