}
  }
  return result.readUtf8()
}

/**
 * Returns the canonical address for [address]. If [address] is an IPv6 address that is mapped to an
 * IPv4 address, this returns the IPv4-mapped address. Otherwise, this returns [address].
 *
 * https://en.wikipedia.org/wiki/IPv6#IPv4-mapped_IPv6_addresses
 */
internal fun canonicalizeInetAddress(address: ByteArray): ByteArray =
  when {

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

            return false;
        }
    }

    /**
     * Formats an IP address string for use in a URL.
     * IPv6 addresses are wrapped in brackets, IPv4 addresses are returned as-is.
     *
     * @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 IP address
     */
    public InetAddress getAddress() {
        return address;
    }

    /**
     * Check if this is an IPv6 address
     *
     * @return true if IPv6, false if IPv4
     */
    public boolean isIpv6() {
        return ipv6;
    }

    /**
     * Check if RSS is supported
     *
     * @return true if RSS capable
     */
    public boolean isRssCapable() {

    Collections.synchronizedMap(mutableMapOf())
  private val requestedHosts: MutableList<String> = Collections.synchronizedList(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
  }

   * Generate an error if the host might be a non-bracketed IPv6 literal.
   *
   * <p>URI formatting requires that IPv6 literals be surrounded by brackets, like "[2001:db8::1]".
   * Chain this call after {@link #fromString(String)} to increase the strictness of the parser, and
   * disallow IPv6 literals that don't contain these brackets.
   *
   * <p>Note that this parser identifies IPv6 literals solely based on the presence of a colon. To

    }
  }

  /** 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() {

          }

          call.eventListener.dnsEnd(call, socketHost, result)
          result
        }

      // Try each address for best behavior in mixed IPv4/IPv6 environments.
      val orderedAddresses =
        when {
          fastFallback -> reorderForHappyEyeballs(addresses)
          else -> addresses
        }

      for (inetAddress in orderedAddresses) {

    InetAddress ipv4 = InetAddresses.forString("1.2.3.4");
    assertThat(InetAddresses.getEmbeddedIPv4ClientAddress(testIp)).isEqualTo(ipv4);

    // Test 6to4 address.
    testIp = (Inet6Address) InetAddresses.forString("2002:0102:0304::1");
    assertTrue(InetAddresses.hasEmbeddedIPv4ClientAddress(testIp));
    ipv4 = InetAddresses.forString("1.2.3.4");