apollo-adminservice/src/main/java/com/ctrip/framework/apollo/adminservice/controller/ItemController.java/ItemController/findDeletedItems
class ItemController:  @GetMapping("/apps/{appId}/clusters/{clusterName}/namespaces/{namespaceName}/items/deleted")
  public List<ItemDTO> findDeletedItems(@PathVariable("appId") String appId,
                                        @PathVariable("clusterName") String clusterName,
                                        @PathVariable("namespaceName") String namespaceName) {
    //get latest release time
    Release latestActiveRelease = releaseService.findLatestActiveRelease(appId, clusterName, namespaceName);
    List<Commit> commits;
    if (Objects.nonNull(latestActiveRelease)) {
      commits = commitService.find(appId, clusterName, namespaceName, latestActiveRelease.getDataChangeCreatedTime(), null);
    } else {
      commits = commitService.find(appId, clusterName, namespaceName, null);
    }

    if (Objects.nonNull(commits)) {
      List<Item> deletedItems = commits.stream()
          .map(item -> ConfigChangeContentBuilder.convertJsonString(item.getChangeSets()).getDeleteItems())
          .flatMap(Collection::stream)
          .collect(Collectors.toList());
      return BeanUtils.batchTransform(ItemDTO.class, deletedItems);
    }
    return Collections.emptyList();
  }