* HTTPS.
   */
  fun handshake(): Handshake?

  /**
   * Returns the protocol negotiated by this connection, or [Protocol.HTTP_1_1] if no protocol
   * has been negotiated. This method returns [Protocol.HTTP_1_1] even if the remote peer is using
   * [Protocol.HTTP_1_0].
   */
  fun protocol(): Protocol

  }

  @Test
  fun upgradeHttps() {
    // org.bouncycastle.tls.TlsNoCloseNotifyException: No close_notify alert received before connection closed
    platform.assumeNotBouncyCastle()

    enableTls(Protocol.HTTP_1_1)
    upgrade()
  }

  @Test
  fun upgradeRefusedByServer() {
    server.enqueue(MockResponse(body = "normal request"))
    val requestWithUpgrade =
      Request
        .Builder()

      "ConnectionReleased",
    )
  }

  @Test
  @Throws(IOException::class)
  fun secondCallEventSequence() {
    enableTls()
    server.protocols = listOf(Protocol.HTTP_2, Protocol.HTTP_1_1)
    server.enqueue(MockResponse())
    server.enqueue(MockResponse())

    client
      .newCall(Request(server.url("/")))
      .execute()
      .close()

    client

  ): Response =
    Response
      .Builder()
      .request(
        Request
          .Builder()
          .url("https://example.com/")
          .build(),
      ).protocol(Protocol.HTTP_1_1)
      .code(code)
      .message("OK")
      .body(responseBody)
      .apply { fn() }
      .build()

    listOf(
      ConnectionSpec.MODERN_TLS,
      ConnectionSpec.COMPATIBLE_TLS,
      ConnectionSpec.CLEARTEXT,
    )
  var protocols: List<Protocol> =
    listOf(
      Protocol.HTTP_1_1,
    )
  var handshakeCertificates: HandshakeCertificates = localhost()
  var sslSocketFactory: SSLSocketFactory? = handshakeCertificates.sslSocketFactory()

      } else {
        javaNetSocket = rawSocket
        protocol =
          when {
            Protocol.H2_PRIOR_KNOWLEDGE in route.address.protocols -> Protocol.H2_PRIOR_KNOWLEDGE
            else -> Protocol.HTTP_1_1
          }
      }

      val connection =
        RealConnection(
          taskRunner = taskRunner,
          connectionPool = connectionPool,
          route = route,

	public static final field Companion Lokhttp3/Protocol$Companion;
	public static final field H2_PRIOR_KNOWLEDGE Lokhttp3/Protocol;
	public static final field HTTP_1_0 Lokhttp3/Protocol;
	public static final field HTTP_1_1 Lokhttp3/Protocol;
	public static final field HTTP_2 Lokhttp3/Protocol;
	public static final field HTTP_3 Lokhttp3/Protocol;
	public static final field QUIC Lokhttp3/Protocol;

      Request
        .Builder()
        .url("https://localhost:1/")
        .build()
    val interceptorResponse =
      Response
        .Builder()
        .request(request)
        .protocol(Protocol.HTTP_1_1)
        .code(200)
        .message("Intercepted!")
        .body("abc".toResponseBody("text/plain; charset=utf-8".toMediaType()))
        .build()
    client =
      client
        .newBuilder()

  private class ClosableCall : FailingCall() {
    private val response =
      Response
        .Builder()
        .request(Request("https://example.com/".toHttpUrl()))
        .protocol(Protocol.HTTP_1_1)
        .message("OK")
        .code(200)
        .body(
          object : ResponseBody() {
            override fun contentType() = null

            override fun contentLength() = -1L

      .assertCode(200)
  }

  private fun enableProtocol(protocol: Protocol) {
    enableTls()
    client =
      client
        .newBuilder()
        .protocols(listOf(protocol, Protocol.HTTP_1_1))
        .build()
    server1.protocols = client.protocols
    server2.protocols = client.protocols
  }

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