.bootstrapDnsHosts(InetAddress.getByName("8.8.4.4"), InetAddress.getByName("8.8.8.8"))
    .build()

  val client = bootstrapClient.newBuilder().dns(dns).build()
```

}

/**
 * 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 {
  return when {
    isMappedIpv4Address(address) -> address.sliceArray(12 until 16)

   00A0; NO-BREAK SPACE
   1680; OGHAM SPACE MARK
   2000; EN QUAD
   2001; EM QUAD
   2002; EN SPACE
   2003; EM SPACE
   2004; THREE-PER-EM SPACE
   2005; FOUR-PER-EM SPACE
   2006; SIX-PER-EM SPACE
   2007; FIGURE SPACE
   2008; PUNCTUATION SPACE
   2009; THIN SPACE
   200A; HAIR SPACE
   200B; ZERO WIDTH SPACE
   202F; NARROW NO-BREAK SPACE
   205F; MEDIUM MATHEMATICAL SPACE

   */
  @Throws(IOException::class)
  fun byteString() = commonByteString()

  /**
   * Returns the response as a character stream.
   *
   * If the response starts with a
   * [Byte Order Mark (BOM)](https://en.wikipedia.org/wiki/Byte_order_mark), it is consumed and
   * used to determine the charset of the response bytes.
   *
   * Otherwise if the response has a `Content-Type` header that specifies a charset, that is used

    // mongolian vowel separator
    assertThat(parse("http://h/\u180e").encodedPath).isEqualTo("/%E1%A0%8E")
    // en quad
    assertThat(parse("http://h/\u2000").encodedPath).isEqualTo("/%E2%80%80")
    // em quad
    assertThat(parse("http://h/\u2001").encodedPath).isEqualTo("/%E2%80%81")
    // en space
    assertThat(parse("http://h/\u2002").encodedPath).isEqualTo("/%E2%80%82")
    // em space

    )
    assertEquals(
      "ISO-8859-1",
      charset.charset(Charsets.US_ASCII)!!.name(),
    )
  }

  @Test fun testTurkishDotlessIWithEnUs() {
    withLocale(Locale("en", "US")) {
      val mediaType = parse("IMAGE/JPEG")
      assertEquals("image", mediaType.type)
      assertEquals("jpeg", mediaType.subtype)
    }
  }

  @Test fun testTurkishDotlessIWithTrTr() {

 * They don't specify whether a specific proxy server should be used or how to authenticate with that proxy server.

They're also concrete: each URL identifies a specific path (like `/square/okhttp`) and query (like `?q=sharks&lang=en`). Each webserver hosts many URLs.

### [Addresses](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-address/)

    server.enqueue(MockResponse().setBody("hello world"))
    val url = server.url("/").toUrl()
    val connection = url.openConnection() as HttpURLConnection
    connection.setRequestProperty("Accept-Language", "en-US")
    val inputStream = connection.inputStream
    val reader = BufferedReader(InputStreamReader(inputStream, StandardCharsets.UTF_8))
    assertThat(connection.getResponseCode()).isEqualTo(HttpURLConnection.HTTP_OK)

    Thread.sleep(10) // Make sure the timestamps are unique.
    val cacheHit =
      executeSynchronously(
        "/",
        "Accept-Language",
        "en-US",
        "Accept-Charset",
        "UTF-8",
      )

    // Check the merged response. The request is the application's original request.
    cacheHit.assertCode(200)
      .assertBody("A")

        .addHeader("Accept-Language", "en-US")
        .build()
    val response1 = client.newCall(request1).execute()
    assertThat(response1.body.string()).isEqualTo("A")
    val request2 =
      Request.Builder()
        .url(url)
        .addHeader("Accept-Language", "fr-CA, fr-FR")
        .addHeader("Accept-Language", "en-US")
        .build()