Filter extends Operator<InputT> implements CompositeOperator<InputT, InputT> { public static <InputT> ByBuilder<InputT> of(PCollection<InputT> input) { return named(null).of(input); } private  Filter(
      @Nullable String name,
      UnaryPredicate<InputT> predicate,
      @Nullable TypeDescriptor<InputT> outputType); static ByBuilder<InputT> of(PCollection<InputT> input); static OfBuilder named(@Nullable String name); UnaryPredicate<InputT> getPredicate(); @Override PCollection<InputT> expand(PCollectionList<InputT> inputs);  }
@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()); }