assertTrue(upper.compareTo(lower) == 0, "expected 1.É < 1.é");
        assertTrue(lower.compareTo(upper) == 0, "expected 1.é > 1.É");
    }

    @Test
    void testCompareDigitToLetter() {
        ComparableVersion seven = new ComparableVersion("7");
        ComparableVersion capitalJ = new ComparableVersion("J");
        ComparableVersion lowerCaseC = new ComparableVersion("c");