public void isNotInstanceOf(Class<?> clazz) {
    if (clazz == null) {
      throw new NullPointerException("clazz");
    }
    if (Platform.classMetadataUnsupported()) {
      throw new UnsupportedOperationException(
          "isNotInstanceOf is not supported under -XdisableClassMetadata");
    }
    if (actual == null) {
      return; // null is not an instance of clazz.
    }
    if (isInstanceOfType(actual, clazz)) {
      failWithActual("expected not to be an instance of", clazz.getName());
      /*
       * TODO(cpovirk): Consider including actual.getClass() if it's not clazz itself but only a
       * subtype.
       */
    }
  }
@Test
  public void isNotInstanceOfSuperclass() {
    expectFailure.whenTesting().that(5).isNotInstanceOf(Number.class);
  }