Debug.println(Debug.LOW, this + ": stopped");
Debug.println(Debug.LOW, "Downlink: stopped");
  public void stopDownlink() {    // setzen, um listen() zu stoppen    this.stop = true;    try {      this.objectInputStream.close();    } catch (java.io.IOException e) {      Debug.println(Debug.HIGH, this + ": error while stopping: " + e);    }    Debug.println(Debug.LOW, this + ": stopped");    this.setDownlinkOwner(null);  }