public final void isNotNaN() {
    if (actual == null) {
      failWithActual(simpleFact("expected a double other than NaN"));
    } else {
      isNotEqualTo(NaN);
    }
  }
@Test
  public void isNotNaNIsNull() {
    expectFailureWhenTestingThat(null).isNotNaN();
    assertFailureKeys("expected a double other than NaN", "but was");
  }