OrderFacade::createFinalPayment

static function createFinalPayment(Order $order)
{
	$price = $order->getPrice();
	$paidSum = $order->getPaymentCollection()->getPaidSum();

	$payment = $order->getPaymentCollection()->createItem();
	$payment->setField('SUM', $price - $paidSum);

	$paySystemId = static::getPaySystemId($payment);
	if ($paySystemId === 0)
	{
		return null;
	}

	$service = SalePaySystemManager::getObjectById($paySystemId);
	$payment->setPaySystemService($service);

	$payment->setPaid('Y');

	return $payment;
}