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