public void testProperty() {
        YearMonth test = new YearMonth(2005, 6);
        assertEquals(test.year(), test.property(DateTimeFieldType.year()));
        assertEquals(test.monthOfYear(), test.property(DateTimeFieldType.monthOfYear()));
        try {
            test.property(DateTimeFieldType.millisOfDay());
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            test.property(null);
            fail();
        } catch (IllegalArgumentException ex) {}
    }