public void testWithers() {
        LocalDate test = new LocalDate(1970, 6, 9, GJ_UTC);
        check(test.withYear(2000), 2000, 6, 9);
        check(test.withMonthOfYear(2), 1970, 2, 9);
        check(test.withDayOfMonth(2), 1970, 6, 2);
        check(test.withDayOfYear(6), 1970, 1, 6);
        check(test.withDayOfWeek(6), 1970, 6, 13);
        check(test.withWeekOfWeekyear(6), 1970, 2, 3);
        check(test.withWeekyear(1971), 1971, 6, 15);
        check(test.withYearOfCentury(60), 1960, 6, 9);
        check(test.withCenturyOfEra(21), 2070, 6, 9);
        check(test.withYearOfEra(1066), 1066, 6, 9);
        check(test.withEra(DateTimeConstants.BC), -1970, 6, 9);
        try {
            test.withMonthOfYear(0);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            test.withMonthOfYear(13);
            fail();
        } catch (IllegalArgumentException ex) {}
    }