if (!stream.requestBody.exhausted()) throw AssertionError("expected exhausted")
      }
    }

  fun cancelStream() =
    apply {
      actions += { stream -> stream.cancel() }
    }

  fun requestIOException() =
    apply {
      actions += { stream ->
        try {
          stream.requestBody.exhausted()
          throw AssertionError("expected IOException")
        } catch (expected: IOException) {
        }

    client =
      client.newBuilder()
        .eventListener(listener)
        .build()
    val body =
      MockStreamHandler()
        .sendResponse("/a has moved!\n", duplexResponseSent)
        .requestIOException()
        .exhaustResponse()
    server.enqueue(
      MockResponse.Builder()
        .clearHeaders()
        .code(HttpURLConnection.HTTP_MOVED_PERM)
        .addHeader("Location: /b")