public void isAbsent() {
    if (actual == null) {
      failWithActual(simpleFact("expected absent optional"));
    } else if (actual.isPresent()) {
      failWithoutActual(
          simpleFact("expected to be absent"), fact("but was present with value", actual.get()));
    }
  }
@Test
  public void isAbsentFailingNull() {
    expectFailureWhenTestingThat(null).isAbsent();
    assertFailureKeys("expected absent optional", "but was");
  }