apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/service/ItemService.java/ItemService/delete
class ItemService:  @Transactional
  public Item delete(long id, String operator) {
    Item item = itemRepository.findById(id).orElse(null);
    if (item == null) {
      throw new IllegalArgumentException("item not exist. ID:" + id);
    }

    item.setDeleted(true);
    item.setDataChangeLastModifiedBy(operator);
    Item deletedItem = itemRepository.save(item);

    auditService.audit(Item.class.getSimpleName(), id, Audit.OP.DELETE, operator);
    return deletedItem;
  }