public void isTrue() {
    if (actual == null) {
      isEqualTo(true); // fails
    } else if (!actual) {
      failWithoutActual(simpleFact("expected to be true"));
    }
  }
@Test
  public void nullIsTrueFailing() {
    expectFailureWhenTestingThat(null).isTrue();
    assertFailureKeys("expected", "but was");
    assertFailureValue("expected", "true");
    assertFailureValue("but was", "null");
  }