*/
  private fun enableProtocol(protocol: Protocol) {
    enableTls()
    client =
      client.newBuilder()
        .protocols(listOf(protocol, Protocol.HTTP_1_1))
        .build()
    server.protocols = client.protocols
  }

  private fun enableTls() {
    client =
      client.newBuilder()
        .sslSocketFactory(

   * message is empty. http://www.w3.org/Protocols/rfc2616/rfc2616-sec6.html#sec6.1
   */
  @Test
  fun emptyMessageAndNoLeadingSpace() {
    val version = 1
    val code = 503
    val statusLine = parse("HTTP/1.$version $code")
    assertThat(statusLine.message).isEqualTo("")
    assertThat(statusLine.protocol).isEqualTo(Protocol.HTTP_1_1)

    sslSocket: SSLSocket,
    hostname: String?,
    protocols: List<Protocol>,
  ) {
    // No TLS extensions if the socket class is custom.
    if (matchesSocket(sslSocket)) {
      // Enable session tickets.
      Conscrypt.setUseSessionTickets(sslSocket, true)

      // Enable ALPN.
      val names = Platform.alpnProtocolNames(protocols)
      Conscrypt.setApplicationProtocols(sslSocket, names.toTypedArray())
    }

  override fun configureTlsExtensions(
    sslSocket: SSLSocket,
    hostname: String?,
    protocols: List<Protocol>,
  ) {
    // No TLS extensions if the socket class is custom.
    socketAdapters.find { it.matchesSocket(sslSocket) }
      ?.configureTlsExtensions(sslSocket, hostname, protocols)
  }

  override fun getSelectedProtocol(sslSocket: SSLSocket): String? =

  override fun configureTlsExtensions(
    sslSocket: SSLSocket,
    hostname: String?,
    protocols: List<Protocol>,
  ) {
    getDelegate(sslSocket)?.configureTlsExtensions(sslSocket, hostname, protocols)
  }

  override fun getSelectedProtocol(sslSocket: SSLSocket): String? {
    return getDelegate(sslSocket)?.getSelectedProtocol(sslSocket)
  }

    val url: HttpUrl = mockWebServer.url("")
    mockWebServer.bodyLimit = 0L
    mockWebServer.protocolNegotiationEnabled = false
    mockWebServer.protocols = listOf()
    val protocols: List<Protocol> = mockWebServer.protocols
    mockWebServer.useHttps(SSLSocketFactory.getDefault() as SSLSocketFactory, false)
    mockWebServer.noClientAuth()
    mockWebServer.requestClientAuth()

  private val http2Connection: Http2Connection,
) : ExchangeCodec {
  @Volatile private var stream: Http2Stream? = null

  private val protocol: Protocol =
    if (Protocol.H2_PRIOR_KNOWLEDGE in client.protocols) {
      Protocol.H2_PRIOR_KNOWLEDGE
    } else {
      Protocol.HTTP_2
    }

  @Volatile
  private var canceled = false

  override fun createRequestBody(
    request: Request,
    contentLength: Long,

  override fun matchesSocket(sslSocket: SSLSocket): Boolean = sslSocketClass.isInstance(sslSocket)

  override fun configureTlsExtensions(
    sslSocket: SSLSocket,
    hostname: String?,
    protocols: List<Protocol>,
  ) {
    // No TLS extensions if the socket class is custom.
    if (matchesSocket(sslSocket)) {
      try {
        // Enable session tickets.
        setUseSessionTickets.invoke(sslSocket, true)

      assertThat(response.protocol).isEqualTo(Protocol.HTTP_2)
    }
  }

  @Test
  fun testOkHttpSecureProxiedHttp1() {
    testRequest {
      val client =
        OkHttpClient.Builder()
          .trustMockServer()
          .proxy(Proxy(Proxy.Type.HTTP, it.remoteAddress()))
          .protocols(listOf(Protocol.HTTP_1_1))
          .build()

      val response =

  }

  @Test
  fun testH2PriorKnowledgeServerFallback() {
    try {
      server.protocols = Arrays.asList(Protocol.H2_PRIOR_KNOWLEDGE, Protocol.HTTP_1_1)
      fail<Any>()
    } catch (expected: IllegalArgumentException) {
      assertThat(expected.message).isEqualTo(
        "protocols containing h2_prior_knowledge cannot use other protocols: " +
          "[h2_prior_knowledge, http/1.1]",
      )
    }
  }

  @Test