if (!isDone()) {
      Listener oldHead = listeners();
      if (oldHead != Listener.TOMBSTONE) {
        Listener newNode = new Listener(listener, executor);
        do {
          newNode.next = oldHead;
          if (casListeners(oldHead, newNode)) {
            return;
          }
          oldHead = listeners(); // re-read
        } while (oldHead != Listener.TOMBSTONE);
      }
    }

      check(!responseBodyOpen && !requestBodyOpen && !socketSourceOpen && !socketSinkOpen)
    }

    val exchangeFinder = this.exchangeFinder!!
    val connection = exchangeFinder.find()
    val codec = connection.newCodec(client, chain)
    val result = Exchange(this, exchangeFinder, codec)
    this.interceptorScopedExchange = result
    this.exchange = result
    withLock {
      this.requestBodyOpen = true