Order::calculateVat

protected function calculateVat()
{
	$vatInfo = parent::calculateVat();

	/** @var Shipment $shipment */
	foreach ($this->getShipmentCollection() as $shipment)
	{
		$rate = $shipment->getVatRate();
		if ($rate)
		{
			$vatInfo['VAT_SUM'] += $shipment->getVatSum();
			$vatInfo['VAT_RATE'] = max($vatInfo['VAT_RATE'], $rate);
		}
	}

	return $vatInfo;
}