public void testPlus_int() {
        Years test2 = Years.years(2);
        Years result = test2.plus(3);
        assertEquals(2, test2.getYears());
        assertEquals(5, result.getYears());
        
        assertEquals(1, Years.ONE.plus(0).getYears());
        
        try {
            Years.MAX_VALUE.plus(1);
            fail();
        } catch (ArithmeticException ex) {
            // expected
        }
    }