public void testMinus_int() {
        Days test2 = Days.days(2);
        Days result = test2.minus(3);
        assertEquals(2, test2.getDays());
        assertEquals(-1, result.getDays());
        
        assertEquals(1, Days.ONE.minus(0).getDays());
        
        try {
            Days.MIN_VALUE.minus(1);
            fail();
        } catch (ArithmeticException ex) {
            // expected
        }
    }