docs: public static boolean isInvoiceAdjustmentItem(final InvoiceItem invoiceItem, final Iterable<InvoiceItem> otherInvoiceItems) {
          // Invoice level credit, i.e. credit adj, but NOT on its on own invoice
          return (InvoiceItemType.CREDIT_ADJ.equals(invoiceItem.getInvoiceItemType()) &&
                  !(Iterables.size(otherInvoiceItems) == 1 &&
                    InvoiceItemType.CBA_ADJ.equals(otherInvoiceItems.iterator().next().getInvoiceItemType()) &&
                    otherInvoiceItems.iterator().next().getInvoiceId().equals(invoiceItem.getInvoiceId()) &&
                    otherInvoiceItems.iterator().next().getAmount().compareTo(invoiceItem.getAmount().negate()) == 0));
      }