public void testFactory_FromCalendarFields() throws Exception {
        GregorianCalendar cal = new GregorianCalendar(1970, 1, 3, 4, 5, 6);
        cal.set(Calendar.MILLISECOND, 7);
        YearMonth expected = new YearMonth(1970, 2);
        assertEquals(expected, YearMonth.fromCalendarFields(cal));
        try {
            YearMonth.fromCalendarFields(null);
            fail();
        } catch (IllegalArgumentException ex) {}
    }