@ValueSource(strings = { "12a", "abc", "123 " })
    void isAllDigitsFalseForNonNumeric(String nonNumeric) {
        assertFalse(UniAddress.isAllDigits(nonNumeric));
    }

    @Test
    void isAllDigitsHandlesEmptyString() {
        // Empty string technically has no non-digit characters, so it returns true
        assertTrue(UniAddress.isAllDigits(""), "isAllDigits should return true for empty string (no non-digits)");
    }