* already split off another thread to stream the request body. Because we permit at most one
   * exchange at a time we break the request stream out from under that writer.
   */
  @Test
  fun duplexWithRedirect() {
    enableProtocol(Protocol.HTTP_2)
    val duplexResponseSent = CountDownLatch(1)
    val requestHeadersEndListener =
      object : EventListener() {
        override fun requestHeadersEnd(