@TestSubtype(suppressGetSupertype = true, suppressGetSubtype = true)
    public <T> Iterable<?> wildcardsMatchByUpperBound(List<? extends T> list) {
      return isSubtype(list);
    }

    @TestSubtype(suppressGetSupertype = true, suppressGetSubtype = true)
    public <T> Iterable<? extends T> wildCardsDoNotMatchByUpperBound(List<?> list) {
      return notSubtype(list);
    }