bytesIn.writeUtf8("custom-foo")
    bytesIn.writeByte(0x0d) // Literal value (len = 13)
    bytesIn.writeUtf8("custom-header")
    bytesIn.writeByte(0x40) // Literal indexed
    bytesIn.writeByte(0x0a) // Literal name (len = 10)
    bytesIn.writeUtf8("custom-bar")
    bytesIn.writeByte(0x0d) // Literal value (len = 13)
    bytesIn.writeUtf8("custom-header")
    bytesIn.writeByte(0x40) // Literal indexed

  }

  @Test
  fun contentLengthHeaderIsForbidden() {
    val multipart = MultipartBody.Builder()
    assertFailsWith<IllegalArgumentException> {
      multipart.addPart(
        headersOf("Content-Length", "13"),
        "Hello, World!".toRequestBody(null),
      )
    }
  }

  @Test
  @Throws(IOException::class)
  fun partAccessors() {
    val body =
      MultipartBody.Builder()

    val request =
      originalRequest.newBuilder()
        .header("Upgrade", "websocket")
        .header("Connection", "Upgrade")
        .header("Sec-WebSocket-Key", key)
        .header("Sec-WebSocket-Version", "13")
        .header("Sec-WebSocket-Extensions", "permessage-deflate")
        .build()
    call = RealCall(webSocketClient, request, forWebSocket = true)
    call!!.enqueue(
      object : Callback {

 * > of this section.  The DNS API server defines the URI used by the
 * > request through the use of a URI Template.
 *
 * [doh_spec]: https://tools.ietf.org/html/draft-ietf-doh-dns-over-https-13
 */
class DnsOverHttps internal constructor(
  @get:JvmName("client") val client: OkHttpClient,
  @get:JvmName("url") val url: HttpUrl,
  @get:JvmName("includeIPv6") val includeIPv6: Boolean,