public final void isNegativeInfinity() {
    isEqualTo(Double.NEGATIVE_INFINITY);
  }
@Test
  public void isNegativeInfinity() {
    assertThat(Double.NEGATIVE_INFINITY).isNegativeInfinity();
    assertThatIsNegativeInfinityFails(1.23);
    assertThatIsNegativeInfinityFails(Double.POSITIVE_INFINITY);
    assertThatIsNegativeInfinityFails(Double.NaN);
    assertThatIsNegativeInfinityFails(null);
  }