yii\authclient\BaseOAuth::restoreAccessToken PHP Method

    protected function restoreAccessToken()
    {
        $token = $this->getState('token');
        if (is_object($token)) {
            /* @var $token OAuthToken */
            if ($token->getIsExpired() && $this->autoRefreshAccessToken) {
                $token = $this->refreshAccessToken($token);
            }
        }
        return $token;
    }