public static <InputT> KeyByBuilder<InputT> of(PCollection<InputT> input) {
    return named(null).of(input);
  }
@Test
  public void testBuild_ImplicitName() {
    final PCollection<String> dataset = TestUtils.createMockDataset(TypeDescriptors.strings());
    final PCollection<Triple<String, Long, Long>> result =
        TopPerKey.of(dataset).keyBy(s -> s).valueBy(s -> 1L).scoreBy(s -> 1L).output();
    final TopPerKey tpk = (TopPerKey) TestUtils.getProducer(result);
    assertFalse(tpk.getName().isPresent());
  }