public static <InputT> ByBuilder<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<String> filtered = Filter.of(dataset).by(s -> !s.equals("")).output();
    final Filter filter = (Filter) TestUtils.getProducer(filtered);
    assertFalse(filter.getName().isPresent());
  }