/**
     * Determines if the given address string represents an IPv6 address.
     * This method validates the address using InetAddress to ensure it's a valid IPv6 address.
     *
     * @param address the IP address string to check
     * @return true if the address is a valid IPv6 address, false otherwise
     */
    public static boolean isIPv6Address(final String address) {
        if (address == null) {
            return false;

					Country:   nil,
				},
				AddressID: org.AddressID,
				Address:   org.Address,
				NestedAddress: NestedAddress{EmbeddedAddress{
					ID:        org.NestedAddress.ID,
					Name:      org.NestedAddress.Name,
					CountryID: org.NestedAddress.CountryID,
					Country:   nil,
				}},
			},
		}, {
			name:     "postal address country",

    InetAddress address = InetAddress.getByName("255.255.255.254");
    assertFalse(InetAddresses.isMaximum(address));

    address = InetAddress.getByName("255.255.255.255");
    assertTrue(InetAddresses.isMaximum(address));

    address = InetAddress.getByName("ffff:ffff:ffff:ffff:ffff:ffff:ffff:fffe");
    assertFalse(InetAddresses.isMaximum(address));

/**
 * Implementation of HappyEyeballs Sorting Addresses.
 *
 * The current implementation does not address any of:
 *  - Async DNS split by IP class
 *  - Stateful handling of connectivity results
 *  - The prioritisation of addresses
 *
 * https://datatracker.ietf.org/doc/html/rfc8305#section-4
 */
internal fun reorderForHappyEyeballs(addresses: List<InetAddress>): List<InetAddress> {
  if (addresses.size < 2) {
    return addresses
  }

        // Given: Multiple addresses with different fail counts
        Address addr1 = mock(Address.class);
        when(addr1.getHostAddress()).thenReturn("10.0.0.1");

        Address addr2 = mock(Address.class);
        when(addr2.getHostAddress()).thenReturn("10.0.0.2");

        when(nameSvc.getAllByName(eq("test.server"), eq(true))).thenReturn(new Address[] { addr1, addr2 });

        NbtAddress[] addresses = new NbtAddress[2];
        // Create dummy NbtAddress objects for testing toString
        addresses[0] = new NbtAddress(mockRecordName, 0xC0A80101, false, 0); // 192.168.1.1
        addresses[1] = new NbtAddress(mockRecordName, 0x0A000005, true, 1); // 10.0.0.5
        addrEntryField.set(nameQueryResponse, addresses);

        String expectedContains = ",addrEntry=[";

import okhttp3.Dns

/**
 * A network that always resolves two IP addresses per host. Use this when testing route selection
 * fallbacks to guarantee that a fallback address is available.
 */
class DoubleInetAddressDns : Dns {
  override fun lookup(hostname: String): List<InetAddress> {
    val addresses = Dns.SYSTEM.lookup(hostname)
    return listOf(addresses[0], addresses[0])
  }

func GetSourceIPFromHeaders(r *http.Request) string {
	var addr string

	if enableXFFHeader {
		if fwd := r.Header.Get(xForwardedFor); fwd != "" {
			// Only grab the first (client) address. Note that '192.168.0.1,
			// 10.1.1.1' is a valid key for X-Forwarded-For where addresses after
			// the first may represent forwarding proxies earlier in the chain.
			s := strings.Index(fwd, ", ")
			if s == -1 {
				s = len(fwd)
			}
			addr = fwd[:s]

    /**
     * Resolves the given host name to an array of IP addresses.
     * The host name is first converted to ASCII using IDN before resolution.
     * IPv6 addresses in bracket notation (e.g., [::1] or [2001:db8::1]) are
     * handled specially by removing the brackets before resolution.
     *
     * @param host the host name to resolve
     * @return an array of IP addresses for the host

    val other = MockWebServer()
    val addressA = InetAddress.getByAddress("localhost", byteArrayOf(127, 0, 0, 1))
    val addressB = InetAddress.getByAddress("localhost", byteArrayOf(127, 0, 0, 2))
    other.use {
      other.start(addressA, 0)

      // Same address is okay.
      other.start(addressA, 0)

      // Same address with bound port is okay.
      other.start(addressA, other.port)