public void testMergePeriod_RP2() {
        MutablePeriod test = new MutablePeriod(100L, PeriodType.millis());
        try {
            test.mergePeriod(new MutablePeriod(11, 12, 13, 14, 15, 16, 17, 18));
            fail();
        } catch (IllegalArgumentException ex) {}
        assertEquals(0, test.getYears());
        assertEquals(0, test.getMonths());
        assertEquals(0, test.getWeeks());
        assertEquals(0, test.getDays());
        assertEquals(0, test.getHours());
        assertEquals(0, test.getMinutes());
        assertEquals(0, test.getSeconds());
        assertEquals(100, test.getMillis());
    }