val request = Request(server1.url("/"))

    server1.enqueue(MockResponse(200))
    server2.enqueue(MockResponse(200))
    server2.enqueue(MockResponse(200))

    println("\n\nRequest to ${server1.inetSocketAddress}")
    executeSynchronously(request)
      .assertSuccessful()
      .assertCode(200)

    println("server1.requestCount ${server1.requestCount}")

	// Only Stateful streams has flow control.
	OpUnblockClMux

	// OpAckMux acknowledges a mux was created.
	OpAckMux

	// OpRequest is a single request + response.
	// MuxID is returned in response.
	OpRequest

	// OpResponse is a response to a single request.
	// FlagPayloadIsErr is used to signify that the payload is a string error converted to byte slice.

func (m *muxClient) roundtrip(h HandlerID, req []byte) ([]byte, error) {
	if m.init {
		return nil, errors.New("mux client already used")
	}
	m.init = true
	m.singleResp = true
	msg := message{
		Op:         OpRequest,
		MuxID:      m.MuxID,
		Handler:    h,
		Flags:      m.BaseFlags | FlagEOF,
		Payload:    req,
		DeadlineMS: uint32(m.deadline.Milliseconds()),
	}
	if m.subroute != nil {
		msg.Flags |= FlagSubroute
	}

    val frResponse = client.newCall(frRequest).execute()
    assertThat(frResponse.body.string()).isEqualTo("A")
    val enRequest =
      Request.Builder()
        .url(url)
        .header("Accept-Language", "en-US")
        .build()
    val enResponse = client.newCall(enRequest).execute()
    assertThat(enResponse.body.string()).isEqualTo("B")
  }

  @Test

		c.handleDisconnectServerMux(m)
	case OpDisconnectClientMux:
		c.handleDisconnectClientMux(m)
	case OpPing:
		c.handlePing(ctx, m)
	case OpPong:
		c.handlePong(ctx, m)
	case OpRequest:
		c.handleRequest(ctx, m, subID)
	case OpAckMux:
		c.handleAckMux(ctx, m)
	case OpConnectMux:
		c.handleConnectMux(ctx, m, subID)
	case OpMuxConnectError:
		c.handleConnectMuxError(ctx, m)