code: public Observable<Page<GenericResourceInner>> listByResourceGroupAsync(final String resourceGroupName) {
          return listByResourceGroupWithServiceResponseAsync(resourceGroupName)
              .map(new Func1<ServiceResponse<Page<GenericResourceInner>>, Page<GenericResourceInner>>() {
                  @Override
                  public Page<GenericResourceInner> call(ServiceResponse<Page<GenericResourceInner>> response) {
                      return response.body();
                  }
              });
      }
docs: Get all the resources for a resource group.
  
  @param resourceGroupName The resource group with the resources to get.
  @throws IllegalArgumentException thrown if parameters fail the validation
  @return the observable to the PagedList&lt;GenericResourceInner&gt; object