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() {

                if (i < len && data[i] == '.') {
                    dots++;
                    i++;
                }
            }
        }

        return false;
    }

    static boolean isAllDigits(final String hostname) {
        for (int i = 0; i < hostname.length(); i++) {
            if (!Character.isDigit(hostname.charAt(i))) {
                return false;
            }
        }
        return true;

            log.warn("Thread join interrupted", e);
            // Restore interrupted status
            Thread.currentThread().interrupt();
        }
    }

    private static boolean isAllDigits(final String hostname) {
        for (int i = 0; i < hostname.length(); i++) {
            if (!Character.isDigit(hostname.charAt(i))) {
                return false;
            }
        }
        return true;