}
            // Add brackets for IPv6
            return "[" + address + "]";
        }
        return address;
    }

    /**
     * Compresses an IPv6 address string to its canonical compressed form.
     * For example, "0:0:0:0:0:0:0:1" becomes "::1"
     *
     * @param ipv6Address the IPv6 address string to compress
     * @return the compressed IPv6 address string
     */

    }

    @Test
    void testAddIPAddresses() throws Exception {
        InetAddress ipv4 = InetAddress.getByName("192.168.1.100");
        InetAddress ipv6 = InetAddress.getByName("2001:db8::1");

        notification.addNewIPAddress(ipv4);
        notification.addNewIPAddress(ipv6);
        notification.addOldIPAddress(ipv4);

        List<WitnessNotification.WitnessIPAddress> newAddresses = notification.getNewIPAddresses();

internal fun reorderForHappyEyeballs(addresses: List<InetAddress>): List<InetAddress> {
  if (addresses.size < 2) {
    return addresses
  }

  val (ipv6, ipv4) = addresses.partition { it is Inet6Address }

  return if (ipv6.isEmpty() || ipv4.isEmpty()) {
    addresses
  } else {
    interleave(ipv6, ipv4)
  }

import java.net.InetAddress;
import java.text.ParseException;
import org.jspecify.annotations.Nullable;

/**
 * A syntactically valid host specifier, suitable for use in a URI. This may be either a numeric IP
 * address in IPv4 or IPv6 notation, or a domain name.
 *
 * <p>Because this class is intended to represent host specifiers which can reasonably be used in a

        }

        /**
         * Checks if this is an IPv4 address.
         *
         * @return true if IPv4
         */
        public boolean isIPv4() {
            return (flags & IPV4) != 0;
        }

        /**
         * Checks if this is an IPv6 address.
         *
         * @return true if IPv6
         */
        public boolean isIPv6() {

  private val hostAddresses: MutableMap<String, List<InetAddress>> = mutableMapOf()
  private val requestedHosts: MutableList<String> = mutableListOf()
  private var nextAddress = 0xff000064L // 255.0.0.100 in IPv4; ::ff00:64 in IPv6.

  /** Sets the results for `hostname`.  */
  operator fun set(
    hostname: String,
    addresses: List<InetAddress>,
  ): FakeDns {
    hostAddresses[hostname] = addresses
    return this
  }

     */
    @Override
    public InetAddress[] resolve(final String host) throws UnknownHostException {
        // Handle IPv6 addresses in bracket notation
        if (host != null && host.length() > 2 && host.startsWith("[") && host.endsWith("]")) {
            // Remove brackets for IPv6 address resolution
            final String ipv6Address = host.substring(1, host.length() - 1);

        IdnDnsResolver resolver = new IdnDnsResolver();

        // Test IPv6 loopback address with brackets
        String host = "[::1]";
        InetAddress[] addresses = resolver.resolve(host);
        assertNotNull(addresses);
        assertTrue(addresses.length > 0);
        // IPv6 loopback can be represented as ::1 or 0:0:0:0:0:0:0:1
        String hostAddress = addresses[0].getHostAddress();

        .testEquals();
  }

  public void testRequireBracketsForIPv6() {
    // Bracketed IPv6 works fine.
    assertEquals("::1", HostAndPort.fromString("[::1]").requireBracketsForIPv6().getHost());
    assertEquals("::1", HostAndPort.fromString("[::1]:80").requireBracketsForIPv6().getHost());
    // Non-bracketed non-IPv6 works fine.
    assertEquals("x", HostAndPort.fromString("x").requireBracketsForIPv6().getHost());

    }
  }

  /** No SNI for literal IPv6 addresses. */
  @Test
  fun ipv6() {
    val recordedRequest = requestToHostnameViaProxy("2607:f8b0:400b:804::200e")
    assertThat(recordedRequest.url.host).isEqualTo("2607:f8b0:400b:804::200e")
    assertThat(recordedRequest.handshakeServerNames).isEmpty()
  }

  /** No SNI for literal IPv4 addresses. */
  @Test
  fun ipv4() {