static function isDynamicVatChargingEnabled()
    {
        if ( isset( $GLOBALS['eZVATManager_isDynamicVatChargingEnabled'] ) )
            return $GLOBALS['eZVATManager_isDynamicVatChargingEnabled'];

        $enabled = is_object( eZVATManager::loadVATHandler() );
        $GLOBALS['eZVATManager_isDynamicVatChargingEnabled'] = $enabled;
        return $enabled;
    }