@SuppressWarnings("deprecation")
    public void testFactoryFieldDifference4() throws Throwable {
        DateTimeFieldType[] types = new DateTimeFieldType[] {
            DateTimeFieldType.year(),
            DateTimeFieldType.monthOfYear(),
            DateTimeFieldType.dayOfWeek(),
        };
        YearMonthDay start = new YearMonthDay(2005, 4, 9);
        Partial end = new Partial(types, new int[] {1, 2, 3});
        try {
            Period.fieldDifference(start, end);
            fail();
        } catch (IllegalArgumentException ex) {}
    }