docs: public Observable<RegistryCredentialsInner> regenerateCredentialsAsync(String resourceGroupName, String registryName) {
          return regenerateCredentialsWithServiceResponseAsync(resourceGroupName, registryName).map(new Func1<ServiceResponse<RegistryCredentialsInner>, RegistryCredentialsInner>() {
              @Override
              public RegistryCredentialsInner call(ServiceResponse<RegistryCredentialsInner> response) {
                  return response.body();
              }
          });
      }