responseSent: CountDownLatch = CountDownLatch(1),
  ) = apply {
    actions += { stream ->
      stream.sink.writeUtf8(s)
      stream.sink.flush()
      responseSent.countDown()
    }
  }

  fun exhaustResponse() =
    apply {
      actions += { stream -> stream.sink.close() }
    }

  fun sleep(
    duration: Long,
    unit: TimeUnit,
  ) = apply {
    actions += { Thread.sleep(unit.toMillis(duration)) }
  }

        .apply {
          receiveRequest("client says hello\n")
          sendResponse("server says hello\n")
          receiveRequest("client says goodbye\n")
          sendResponse("server says goodbye\n")
          exhaustResponse()
          exhaustRequest()
        }
    server.enqueue(socketHandler.upgradeResponse())

    client
      .newCall(
        upgradeRequest(),
      ).execute()
      .use { response ->