docs: public Observable<ProviderInner> unregisterAsync(String resourceProviderNamespace) {
          return unregisterWithServiceResponseAsync(resourceProviderNamespace).map(new Func1<ServiceResponse<ProviderInner>, ProviderInner>() {
              @Override
              public ProviderInner call(ServiceResponse<ProviderInner> response) {
                  return response.body();
              }
          });
      }