code: public Observable<Page<ResourceMetricInner>> listMetricsAsync(final String resourceGroupName, final String name) {
          return listMetricsWithServiceResponseAsync(resourceGroupName, name)
              .map(new Func1<ServiceResponse<Page<ResourceMetricInner>>, Page<ResourceMetricInner>>() {
                  @Override
                  public Page<ResourceMetricInner> call(ServiceResponse<Page<ResourceMetricInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Get metrics for an App Serice plan.
  Get metrics for an App Serice plan.
  
  @param resourceGroupName Name of the resource group to which the resource belongs.
  @param name Name of the App Service plan.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;ResourceMetricInner&gt; object