code: public Observable<ServiceResponse<Page<ResourceMetricInner>>> listMultiRolePoolInstanceMetricsWithServiceResponseAsync(final String resourceGroupName, final String name, final String instance, final Boolean details) {
          return listMultiRolePoolInstanceMetricsSinglePageAsync(resourceGroupName, name, instance, details)
              .concatMap(new Func1<ServiceResponse<Page<ResourceMetricInner>>, Observable<ServiceResponse<Page<ResourceMetricInner>>>>() {
                  @Override
                  public Observable<ServiceResponse<Page<ResourceMetricInner>>> call(ServiceResponse<Page<ResourceMetricInner>> page) {
                      String nextPageLink = page.body().nextPageLink();
                      if (nextPageLink == null) {
                          return Observable.just(page);
                      }
                      return Observable.just(page).concatWith(listMultiRolePoolInstanceMetricsNextWithServiceResponseAsync(nextPageLink));
                  }
              });
      }
docs: Get metrics for a specific instance of a multi-role pool of an App Service Environment.
  Get metrics for a specific instance of a multi-role pool of an App Service Environment.
  
  @param resourceGroupName Name of the resource group to which the resource belongs.
  @param name Name of the App Service Environment.
  @param instance Name of the instance in the multi-role pool.
  @param details Specify &lt;code&gt;true&lt;/code&gt; to include instance details. The default is &lt;code&gt;false&lt;/code&gt;.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;ResourceMetricInner&gt; object