docs: public void buildForMissingInterval(@Nullable final LocalDate startDate, @Nullable final LocalDate endDate, @Nullable final UUID targetInvoiceId, final Collection<Item> output, final boolean addRepair) {
          final Item item = createNewItem(startDate, endDate, targetInvoiceId, addRepair);
          if (item != null) {
              output.add(item);
          }
      }