会员模块检查登录放到每一个方法中是有什么特别的意思吗

比如这里的

Yii::$app->user->isGuest

public function actionIndex()
    {
        if (Yii::$app->user->isGuest) {
            return Yii::$service->url->redirectByUrlKey('customer/account/login');
        }
        $data = $this->getBlock()->getLastData();

        return $this->render($this->action->id, $data);
    }

    public function actionEdit()
    {
        if (Yii::$app->user->isGuest) {
            return Yii::$service->url->redirectByUrlKey('customer/account/login');
        }
        $data = $this->getBlock()->getLastData();

        return $this->render($this->action->id, $data);
    }

    public function actionChangecountry()
    {
        if (Yii::$app->user->isGuest) {
            return Yii::$service->url->redirectByUrlKey('customer/account/login');
        }
        $this->getBlock('edit')->getAjaxState();
    }