apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/service/ItemService.java/ItemService/findItemsWithOrdered
class ItemService:  public List<Item> findItemsWithOrdered(Long namespaceId) {
    List<Item> items = itemRepository.findByNamespaceIdOrderByLineNumAsc(namespaceId);
    if (items == null) {
      return Collections.emptyList();
    }
    return items;
  }