public void testPropertySetCopyMonth() {
        LocalDateTime test = new LocalDateTime(1972, 6, 9, 10, 20, 30, 40);
        LocalDateTime copy = test.monthOfYear().setCopy(12);
        check(test, 1972, 6, 9, 10, 20, 30, 40);
        check(copy, 1972, 12, 9, 10, 20, 30, 40);
        
        test = new LocalDateTime(1972, 1, 31, 10, 20, 30, 40);
        copy = test.monthOfYear().setCopy(2);
        check(copy, 1972, 2, 29, 10, 20, 30, 40);
        
        try {
            test.monthOfYear().setCopy(13);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            test.monthOfYear().setCopy(0);
            fail();
        } catch (IllegalArgumentException ex) {}
    }