i’m currently working with the Mustangproject to create an XRechnung invoice. Allowances on document level are working fine. But when i try to add an allowance on invoice line level error is: The method addAllowance(IZUGFeRDAllowanceCharge) is undefined for the type Product.
as well as for Item (in case i cant read the documentation): The method addAllowance(IZUGFeRDAllowanceCharge) is undefined for the type Item

The Code:

 IZUGFeRDAllowanceCharge allowance = new Allowance()
                    .setPercent(new BigDecimal(12))
                    .setReason("Reason")
                    .setCategoryCode("test")
                    .setTaxPercent(new BigDecimal(19))
                    .setTotalAmount(new BigDecimal(100));

            Item item = new Item(null, null, null);
            item.setProduct(new Product(description, name, unit, vATPercent));
            item.setPrice(invoiceLine.priceDetails.itemNetPrice.getContent());
            item.setQuantity(invoiceLine.invoicedQuantity.getContent());
            Product product = new Product(null, null, null, null);
            item.addAllowance(allowance);

I want to add Allowances and Charges on Invoice Line level (for 1 product only).
The addAllowance method wont get recognized.