code: String mementoFor(ExcelModuleDemoToDoItemBulkUpdateLineItem lineItem) {
          final Memento memento = mementoService.create();
          memento.set("toDoItem", bookmarkService.bookmarkFor(lineItem.getToDoItem()));
          memento.set("description", lineItem.getDescription());
          memento.set("category", lineItem.getCategory());
          memento.set("subcategory", lineItem.getSubcategory());
          memento.set("cost", lineItem.getCost());
          memento.set("complete", lineItem.isComplete());
          memento.set("dueBy", lineItem.getDueBy());
          memento.set("notes", lineItem.getNotes());
          memento.set("ownedBy", lineItem.getOwnedBy());
          return memento.asString();
      }
docs: //////////////////////////////////////