public void testPropertySetCopyDay() {
        LocalDate test = new LocalDate(1972, 6, 9);
        LocalDate copy = test.dayOfMonth().setCopy(12);
        check(test, 1972, 6, 9);
        check(copy, 1972, 6, 12);
        
        try {
            test.dayOfMonth().setCopy(31);
            fail();
        } catch (IllegalArgumentException ex) {}
        try {
            test.dayOfMonth().setCopy(0);
            fail();
        } catch (IllegalArgumentException ex) {}
    }