public static function restore($backup_id)
 {
     $backup_data = self::get_backup_by_id($backup_id);
     $backup_dir = SNS_BACKUPS_PATH . $backup_data->filename;
     $backup_file = $backup_dir . '.zip';
     if (!is_file($backup_file)) {
         throw new Sns_Exception_Not_Found('File not found ' . $backup_file);
     }
     self::restore_from_file($backup_dir, $backup_file);
     Sns_Backup::save_restore($backup_id);
 }