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

    multipartReader.use {
      while (true) {
        val part = multipartReader.nextPart() ?: break
        process(part.headers, part.body)
      }
    }
    ```

 *  New: `MediaType.parameter()` gets a parameter like `boundary` from a media type like
    `multipart/mixed; boundary="abc"`.

        boundary = "simple boundary",
        source = Buffer().writeUtf8(multipart),
      )

    val part = parts.nextPart()!!
    assertThat(part.body.readUtf8()).isEqualTo("abcd\r\n--simple boundar\r\n\r\nefgh")

    assertThat(parts.nextPart()).isNull()
  }

  @Test fun `do not need to read entire part`() {
    val multipart =
      """
      |--simple boundary
      |
      |abcd
      |efgh

    CipherSuite.TLS_CHACHA20_POLY1305_SHA256,
    CipherSuite.TLS_AES_128_CCM_SHA256,
    CipherSuite.TLS_AES_128_CCM_8_SHA256,
  )

/**
 * A TLS 1.3 only Connection Spec. This will be eventually be exposed
 * as part of MODERN_TLS or folded into the default OkHttp client once published and
 * available in JDK11 or Conscrypt.
 */
private val TLS_13 =
  ConnectionSpec.Builder(true)
    .cipherSuites(*TLS13_CIPHER_SUITES.toTypedArray())

 *    or after it ends.
 *
 *  * **A public key.** This cryptographic key is used for asymmetric encryption digital signatures.
 *    Note that the private key is not a part of the certificate!
 *
 *  * **A signature issued by another certificate's private key.** This mechanism allows a trusted
 *    third-party to endorse a certificate. Third parties should only endorse certificates once

 *   while (true) {
 *     val part = multipartReader.nextPart() ?: break
 *     process(part.headers, part.body)
 *   }
 * }
 * ```
 *
 * Note that [nextPart] will skip any unprocessed data from the preceding part. If the preceding
 * part is particularly large or if the underlying source is particularly slow, the [nextPart] call
 * may be slow!
 *

    val size: Int = multipartBody.size()
    val parts: List<MultipartBody.Part> = multipartBody.parts()
  }

  @Test @Disabled
  fun multipartBodyPart() {
    val multipartBody: MultipartBody = MultipartBody.Builder().build()
    val part: MultipartBody.Part = multipartBody.part(0)
    val headers: Headers? = part.headers()
    val body: RequestBody = part.body()
  }

  @Test @Disabled
  fun okHttpClient() {

attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works; and (d) If the Work includes a "NOTICE" text file as part of its distribution, then any Derivative Works that You distribute must include a readable copy of the attribution notices contained within such NOTICE file, excluding those notices that do not pertain to any part of the Derivative Works, in at least one of the following places: within a NOTICE text file distributed...

  fun onePartRequired() {
    assertFailsWith<IllegalStateException> {
      MultipartBody.Builder().build()
    }.also { expected ->
      assertThat(expected.message)
        .isEqualTo("Multipart body must have at least one part.")
    }
  }

  @Test
  fun singlePart() {
    val expected =
      """
      |--123
      |
      |Hello, World!
      |--123--
      |
      """.trimMargin().replace("\n", "\r\n")

   *
   * A push promise contains all the headers that pertain to a server-initiated request, and a
   * `promisedStreamId` to which response frames will be delivered. Push promise frames are sent as
   * a part of the response to `streamId`. The `promisedStreamId` has a priority of one greater than
   * `streamId`.
   *
   * @param streamId client-initiated stream ID.  Must be an odd number.

     *
     * A push promise contains all the headers that pertain to a server-initiated request, and a
     * `promisedStreamId` to which response frames will be delivered. Push promise frames are sent
     * as a part of the response to `streamId`.
     *
     * @param streamId client-initiated stream ID.  Must be an odd number.
     * @param promisedStreamId server-initiated stream ID.  Must be an even number.