code: public List<NaaccrValidationError> getAllValidationErrors() {
          List<NaaccrValidationError> results = new ArrayList<>(getValidationErrors());
          results.addAll(getItems().stream().filter(item -> item.getValidationError() != null).map(Item::getValidationError).collect(Collectors.toList()));
          for (Tumor tumor : getTumors())
              results.addAll(tumor.getAllValidationErrors());
          return results;
      }
docs: This methods returns all the validation errors on the patient, any of its items and any of its tumors.
  @return collection of validation errors, maybe empty but never null