docs: public Observable<DiskInner> createOrUpdateAsync(String resourceGroupName, String diskName, DiskInner disk) {
          return createOrUpdateWithServiceResponseAsync(resourceGroupName, diskName, disk).map(new Func1<ServiceResponse<DiskInner>, DiskInner>() {
              @Override
              public DiskInner call(ServiceResponse<DiskInner> response) {
                  return response.body();
              }
          });
      }