public function getUserGroupNames()
    {
        /** @var OxpsPaymorrowOxUser|oxUser $this */

        /** @var oxList $oGroups */
        if ( !( $oGroups = $this->getUserGroups() ) ) {
            return '';
        }

        $aGroups = array();

        foreach ( $oGroups as $oGroup ) {
            if ( $this->_isGroupValid( $oGroup ) ) {
                $aGroups[] = $oGroup->oxgroups__oxtitle->value;
            }
        }

        return implode( ', ', $aGroups );
    }