OrderBuilderRest::setQuantityShipmentItem

protected function setQuantityShipmentItem(ShipmentItem $shipmentItem, $value, $oldValue)
{
	$deltaQuantity = $value - $oldValue;

	if($shipmentItem->getQuantity() + $deltaQuantity == 0)
	{
		$r = $shipmentItem->delete();
	}
	else
	{
		$r = $shipmentItem->setField(
			"QUANTITY",
			$shipmentItem->getQuantity() + $deltaQuantity
		);
	}

	return $r;
}