code: @Override
      public void onWriteError(Exception e, List<? extends ContentItem> items) {
          StringBuilder sb = new StringBuilder();
          for (ContentItem item : items) {
              sb.append(item.getContentId() + ", ");
          }
  
          String message = "Error writing item(s): " + e.getMessage() + ": items=" + sb.toString();
          this.errors.add(message);
          log.error(message, e);
      }
docs: Method defined in ItemWriteListener interface