IsNegativeInfinity extends TypeSafeMatcher<N> { @Override public void describeTo(final Description description) { description.appendText("a value equals to negative infinity"); }  static Matcher<N> negativeInfinity(); @Override void describeTo(final Description description);  }
@Test public void testDescribeTo() throws Exception { assertIsDescribedTo("a value equals to negative infinity", isNegativeInfinityMatcher); }