public function setEnabled(string $enabled = "T") : CNabuDataObject
    {
        if ($enabled === null) {
            throw new ENabuCoreException(
                    ENabuCoreException::ERROR_NULL_VALUE_NOT_ALLOWED_IN,
                    array("\$enabled")
            );
        }
        $this->setValue('nb_site_lang_enabled', $enabled);
        
        return $this;
    }