void isAllDigitsTrueForPureNumeric(String numeric) {
        assertTrue(UniAddress.isAllDigits(numeric));
    }

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

    @Test
    void isAllDigitsHandlesEmptyString() {