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