public static function set_state_running($running = true) {
        if ($running === true) {
            if (self::get_automated_backup_state() === self::STATE_RUNNING) {
                throw new backup_helper_exception('backup_automated_already_running');
            }
            set_config('backup_auto_running', '1', 'backup');
        } else {
            unset_config('backup_auto_running', 'backup');
        }
        return true;
    }