code: public Observable<Page<AppServiceEnvironmentResourceInner>> listByResourceGroupAsync(final String resourceGroupName) {
          return listByResourceGroupWithServiceResponseAsync(resourceGroupName)
              .map(new Func1<ServiceResponse<Page<AppServiceEnvironmentResourceInner>>, Page<AppServiceEnvironmentResourceInner>>() {
                  @Override
                  public Page<AppServiceEnvironmentResourceInner> call(ServiceResponse<Page<AppServiceEnvironmentResourceInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Get all App Service Environments in a resource group.
  Get all App Service Environments in a resource group.
  
  @param resourceGroupName Name of the resource group to which the resource belongs.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;AppServiceEnvironmentResourceInner&gt; object