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