public function addRole(CNabuSiteTargetCTARole $nb_role)
    {
        if ($nb_role->isValueNumeric(NABU_ROLE_FIELD_ID) || $nb_role->isValueGUID(NABU_ROLE_FIELD_ID)) {
            $nb_role->setSiteTargetCTA($this);
            $this->nb_site_target_cta_role_list->addItem($nb_role);
        }

        return $nb_role;
    }