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