public void isFalse() {
    if (actual == null) {
      isEqualTo(false); // fails
    } else if (actual) {
      failWithoutActual(simpleFact("expected to be false"));
    }
  }
@Test
  public void isFalseFailing() {
    expectFailureWhenTestingThat(true).isFalse();
    assertFailureKeys("expected to be false");
  }