@Override
  public Iterable<Class<? extends PipelineOptions>> getPipelineOptions() {
    return ImmutableList.of(HadoopFileSystemOptions.class);
  }
@Test
  public void testServiceLoader() {
    for (PipelineOptionsRegistrar registrar :
        Lists.newArrayList(ServiceLoader.load(PipelineOptionsRegistrar.class).iterator())) {
      if (registrar instanceof HadoopFileSystemOptionsRegistrar) {
        assertThat(
            registrar.getPipelineOptions(),
            Matchers.<Class<?>>contains(HadoopFileSystemOptions.class));
        return;
      }
    }
    fail("Expected to find " + HadoopFileSystemOptionsRegistrar.class);
  }