code: public Observable<ServiceResponse<List<MetricsResultsItem>>> getMultipleWithServiceResponseAsync(String appId, List<MetricsPostBodySchema> body) {
          if (appId == null) {
              throw new IllegalArgumentException("Parameter appId is required and cannot be null.");
          }
          if (body == null) {
              throw new IllegalArgumentException("Parameter body is required and cannot be null.");
          }
          Validator.validate(body);
          return service.getMultiple(appId, body, this.client.acceptLanguage(), this.client.userAgent())
              .flatMap(new Func1<Response<ResponseBody>, Observable<ServiceResponse<List<MetricsResultsItem>>>>() {
                  @Override
                  public Observable<ServiceResponse<List<MetricsResultsItem>>> call(Response<ResponseBody> response) {
                      try {
                          ServiceResponse<List<MetricsResultsItem>> clientResponse = getMultipleDelegate(response);
                          return Observable.just(clientResponse);
                      } catch (Throwable t) {
                          return Observable.error(t);
                      }
                  }
              });
      }
docs: Retrieve metric data.
  Gets metric values for multiple metrics.
  
  @param appId ID of the application. This is Application ID from the API Access settings blade in the Azure portal.
  @param body The batched metrics query.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the List&lt;MetricsResultsItem&gt; object