php – How to properly use validateAuthKey() function in yii2?

Question:

I did some research on the standard example and found out that the validateAuthKey() function is not called at all. Why is it needed then, how to call it correctly, how to work with it correctly?

public function validateAuthKey($authKey)
    {
        Yii::info('test ================');
        return $this->authKey === $authKey;
    }

Answer:

validateAuthKey() validates $authKey – the hash stored in the cookie. Called for cookie authentication in yii\web\User::loginByCookie when $enableAutoLogin = true

    protected function loginByCookie()
        {
            ...
            if ($identity->validateAuthKey($authKey)) {
                if ($this->beforeLogin($identity, true, $duration)) {
                    $this->switchIdentity($identity, $this->autoRenewCookie ? $duration : 0);
                    $ip = Yii::$app->getRequest()->getUserIP();
                    Yii::info("User '$id' logged in from $ip via cookie.", __METHOD__);
                    $this->afterLogin($identity, true, $duration);
                }
            }
            ... 
        }