}

  public void testCompound_instance() {
    Comparator<String> comparator = byCharAt(1).compound(byCharAt(0));
    Helpers.testComparator(
        comparator,
        ImmutableList.of("red", "yellow", "violet", "blue", "indigo", "green", "orange"));
  }

  public void testCompound_instance_generics() {
    Ordering<Object> objects = Ordering.explicit((Object) 1);
    Ordering<Number> numbers = Ordering.explicit((Number) 1);