*
     * @param address the IP address string to format
     * @return the formatted address (IPv6 with brackets, IPv4 unchanged)
     */
    public static String formatForUrl(final String address) {
        if (address == null) {
            return null;
        }
        if (isIPv6Address(address)) {
            // If already has brackets, return as-is

        assertEquals("[::1]", IpAddressUtil.formatForUrl("::1"));
        assertEquals("[2001:db8::1]", IpAddressUtil.formatForUrl("2001:db8::1"));
        assertEquals("[fe80::1]", IpAddressUtil.formatForUrl("fe80::1"));

        // IPv6 addresses already with brackets - should not double-wrap
        assertEquals("[::1]", IpAddressUtil.formatForUrl("[::1]"));