rhertogh / yii2-oauth2-server

src/models/traits/Oauth2ExpiryDateTimeTrait.php

<?php

namespace rhertogh\Yii2Oauth2Server\models\traits;

use DateTimeImmutable;

trait Oauth2ExpiryDateTimeTrait
{
    /**
     * @inheritDoc
     */
    public function getExpiryDateTime()
    {
        return $this->expiry_date_time;
    }

    /**
     * @inheritDoc
     */
    public function setExpiryDateTime(DateTimeImmutable $dateTime)
    {
        $this->expiry_date_time = $dateTime;

The property expiry_date_time does not exist. Although not strictly required by PHP, it is generally a best practice to declare properties explicitly.

    }
}