docs: public UpdateItemResponse updateItem(UpdateItemRequest request) 
              throws BceClientException, BceServiceException {
          checkNotNull(request, "request should not be null.");
          InternalRequest httpRequest = createRequestUnderInstance(HttpMethodName.POST,
                  MolaDbConstants.URI_TABLE, 
                  request.getTableName(),
                  MolaDbConstants.URI_ITEM);
          fillInHeadAndBody(request, httpRequest);
          UpdateItemResponse ret = this.invokeHttpClient(httpRequest, UpdateItemResponse.class);
          return ret;
      }