public function setExclusive(string $exclusive = "F") : CNabuDataObject
    {
        if ($exclusive === null) {
            throw new ENabuCoreException(
                    ENabuCoreException::ERROR_NULL_VALUE_NOT_ALLOWED_IN,
                    array("\$exclusive")
            );
        }
        $this->setValue('nb_user_group_type_exclusive', $exclusive);
        
        return $this;
    }