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")