eZ\Publish\Core\Repository\Values\User\User::__isset PHP Method

    public function __isset($property)
    {
        if ($property === 'contentInfo') {
            return true;
        }
        if ($property === 'id') {
            return true;
        }
        if ($property === 'versionInfo') {
            return true;
        }
        if ($property === 'fields') {
            return true;
        }
        return parent::__isset($property);
    }