public class PurchaseOrderType
    implements MergeFrom//, ...

    // ...    

        public Object createNewInstance() {
        return new PurchaseOrderType();
    }

    public void mergeFrom(Object left, Object right) {
        final MergeStrategy strategy = JAXBMergeStrategy.INSTANCE;
        mergeFrom(null, null, left, right, strategy);
    }

    public void mergeFrom(ObjectLocator leftLocator, ObjectLocator rightLocator, Object left, Object right, MergeStrategy strategy) {
        if (right instanceof PurchaseOrderType) {
            final PurchaseOrderType target = this;
            final PurchaseOrderType leftObject = ((PurchaseOrderType) left);
            final PurchaseOrderType rightObject = ((PurchaseOrderType) right);
            {
                USAddress leftShipTo;
                leftShipTo = leftObject.getShipTo();
                USAddress rightShipTo;
                rightShipTo = rightObject.getShipTo();
                target.setShipTo(((USAddress) strategy.merge(LocatorUtils.property(leftLocator, "shipTo", leftShipTo), LocatorUtils.property(rightLocator, "shipTo", rightShipTo), leftShipTo, rightShipTo)));
            }
            {
                USAddress leftBillTo;
                leftBillTo = leftObject.getBillTo();
                USAddress rightBillTo;
                rightBillTo = rightObject.getBillTo();
                target.setBillTo(((USAddress) strategy.merge(LocatorUtils.property(leftLocator, "billTo", leftBillTo), LocatorUtils.property(rightLocator, "billTo", rightBillTo), leftBillTo, rightBillTo)));
            }
            // ...
        }
    }


    // ...
}

-Xmergeable-mergeStrategyClass=com.acme.foo.CustomMergeStrategy