above. See [Jetty's overview][jetty_8_252] of the API change and its consequences.

 *  New: `MultipartReader` is a streaming decoder for [MIME multipart (RFC 2045)][rfc_2045]
    messages. It complements `MultipartBody` which is our streaming encoder.

    ```kotlin
    val response: Response = call.execute()
    val multipartReader = MultipartReader(response.body!!)

    multipartReader.use {

    // We've successfully read a byte.
    address[b++] = value.toByte()
  }

  // Check for too few groups. We wanted exactly four.
  return b == addressOffset + 4
}

/** Encodes an IPv6 address in canonical form according to RFC 5952. */
internal fun inet6AddressToAscii(address: ByteArray): String {
  // Go through the address looking for the longest run of 0s. Each group is 2-bytes.

    assertFailsWith<ProtocolException> {
      derReader.read("test") {}
    }.also { expected ->
      assertThat(expected.message)
        .isEqualTo("length encoded with more than 8 bytes is not supported")
    }
  }

  @Test fun `encode tag and length`() {
    val buffer = Buffer()
    val derWriter = DerWriter(buffer)

    derWriter.write("test", tagClass = DerHeader.TAG_CLASS_UNIVERSAL, tag = 30L) {

  fun toUriWithControlCharacters() {
    // Percent-encoded in the path.
    assertThat("http://host/a\u0000b".toHttpUrl().toUri())
      .isEqualTo(URI("http://host/a%00b"))
    assertThat("http://host/a\u0080b".toHttpUrl().toUri())
      .isEqualTo(URI("http://host/a%C2%80b"))
    assertThat("http://host/a\u009fb".toHttpUrl().toUri())
      .isEqualTo(URI("http://host/a%C2%9Fb"))
    // Percent-encoded in the query.

        }

        if (!logBody || requestBody == null) {
          logger.log("--> END ${request.method}")
        } else if (bodyHasUnknownEncoding(request.headers)) {
          logger.log("--> END ${request.method} (encoded body omitted)")
        } else if (requestBody.isDuplex()) {
          logger.log("--> END ${request.method} (duplex request body omitted)")
        } else if (requestBody.isOneShot()) {

        .build()
    val certificate = heldCertificate.certificate
    assertThat(certificate.getSubjectX500Principal().name).isEqualTo(
      "CN=cash.app,OU=cash",
    )
  }

  /** Confirm golden values of encoded PEMs.  */
  @Test
  fun pems() {
    val keyFactory = KeyFactory.getInstance("RSA")
    val publicKeyBytes =
      (
        "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCApFHhtrLan28q+oMolZuaTfWBA0V5aM" +

  )
  fun keyPair(): KeyPair = keyPair

  /**
   * Returns the certificate encoded in [PEM format][rfc_7468].
   *
   * [rfc_7468]: https://tools.ietf.org/html/rfc7468
   */
  fun certificatePem(): String = certificate.certificatePem()

  /**
   * Returns the private key encoded in [PKCS #8][rfc_5208] [PEM format][rfc_7468].
   *
   * [rfc_5208]: https://tools.ietf.org/html/rfc5208

     * certificates are base64-encoded and appear each on their own line. The next line contains the
     * length of the local certificate chain. These certificates are also base64-encoded and appear
     * each on their own line. A length of -1 is used to encode a null array. The last line is
     * optional. If present, it contains the TLS version.
     */

  companion object {
    @JvmField
    val DEFAULT = Builder().build()

    @JvmStatic
    fun X509Certificate.sha1Hash(): ByteString = publicKey.encoded.toByteString().sha1()

    @JvmStatic
    fun X509Certificate.sha256Hash(): ByteString = publicKey.encoded.toByteString().sha256()

    /**
     * Returns the SHA-256 of `certificate`'s public key.
     *

    fun body(body: MockResponseBody) =
      apply {
        setHeader("Content-Length", body.contentLength)
        this.body = body
      }

    /** Sets the response body to the UTF-8 encoded bytes of [body]. */
    fun body(body: String): Builder = body(Buffer().writeUtf8(body))

    fun streamHandler(streamHandler: StreamHandler) =
      apply {
        this.streamHandler = streamHandler
      }