public static <T> PTransform<PCollection<T>, PCollection<ValueInSingleWindow<T>>> windows() {
    return new Window<>();
  }
@Test
  @Category({NeedsRunner.class, UsesTestStream.class})
  public void globalWindowNoKeys() {
    PCollection<ValueInSingleWindow<String>> result =
        pipeline
            .apply(
                TestStream.create(StringUtf8Coder.of())
                    .addElements(TimestampedValue.of("dei", new Instant(123L)))
                    .advanceWatermarkToInfinity())
            .apply(Reify.windows());
    PAssert.that(result)
        .containsInAnyOrder(
            ValueInSingleWindow.of(
                "dei", new Instant(123L), GlobalWindow.INSTANCE, PaneInfo.NO_FIRING));
    pipeline.run();
  }