Automattic\WP\Cron_Control\Singleton::instance PHP 메소드

    public static function instance()
    {
        $caller = get_called_class();
        if (!isset(self::$__instances[$caller])) {
            self::$__instances[$caller] = new $caller();
            self::$__instances[$caller]->class_init();
        }
        return self::$__instances[$caller];
    }