code: @Override
      public void readFragmentFrom(MwsReader r) {
          invoiceRequirement = r.read("InvoiceRequirement", String.class);
          buyerSelectedInvoiceCategory = r.read("BuyerSelectedInvoiceCategory", String.class);
          invoiceTitle = r.read("InvoiceTitle", String.class);
          invoiceInformation = r.read("InvoiceInformation", String.class);
      }
docs: Read members from a MwsReader.
  
  @param r
  The reader to read from.