code: public Observable<Page<AvailabilitySetInner>> listByResourceGroupAsync(String resourceGroupName) {
          return listByResourceGroupWithServiceResponseAsync(resourceGroupName).map(new Func1<ServiceResponse<List<AvailabilitySetInner>>, Page<AvailabilitySetInner>>() {
              @Override
              public Page<AvailabilitySetInner> call(ServiceResponse<List<AvailabilitySetInner>> response) {
                  PageImpl<AvailabilitySetInner> page = new PageImpl<>();
                  page.setItems(response.body());
                  return page;
              }
          });
      }
docs: Lists all availability sets in a resource group.
  
  @param resourceGroupName The name of the resource group.
  @return the observable to the List&lt;AvailabilitySetInner&gt; object