Yii2: Why is data not being written to the session?

Question

Yii

Good afternoon.
Why is data not being written to the session?

$session = Yii::$app->session;
$session->open();
$session->set('language', 'ru');
print_r($session);

The response looks like this (nothing got into the session):

yii\web\Session#1
(
    [flashParam] => '__flash'
    [handler] => null
    [yii\web\Session:_cookieParams] => [
        'httponly' => true
    ]
    [yii\web\Session:_hasSessionId] => null
    [yii\base\Component:_events] => []
    [yii\base\Component:_behaviors] => null
)

Answer 1

Good morning.
Everything is written beautifully.

$session = Yii::$app->session;
$session->open();
if($session->isActive){
    $session->set('language', 'ru');
}

if($session->has('language')){
   echo $session['language'];
}else{
   echo 'no';
}

More here