public static FromEndOfWindow pastEndOfWindow() {
    return new FromEndOfWindow();
  }
@Test
  public void testEarlyAndLateFiringsToString() {
    Trigger trigger =
        AfterWatermark.pastEndOfWindow()
            .withEarlyFirings(StubTrigger.named("t1"))
            .withLateFirings(StubTrigger.named("t2"));

    assertEquals(
        "AfterWatermark.pastEndOfWindow().withEarlyFirings(t1).withLateFirings(t2)",
        trigger.toString());
  }