Yii2 Autologin

I was wondering if anyone could explain how the cookie based login works in Yii2. I see the loginByCookie method in yii\web\user but I am confused on what file and method actually call it to log the user in? Thanks in advance!

if you call yii::$app->user->identity then app will call yii\web\user::getIdentity and next will call


All makes sense now. Thanks!