DownlinkOwner owner;
DownlinkOwner owner = this.downlinkOwner;
    private synchronized void listen() {        Command tmpCommand;        DownlinkOwner owner;        while (!stop) {            owner=this.downlinkOwner;            try {                tmpCommand = (Command)objectInputStream.readObject();                Debug.println(this+" received: " + tmpCommand);                if(owner!=null){                owner.processMsg(tmpCommand);                }                this.sleep(this.LISTEN_DELAY);            }            catch (Exception e) {                Debug.println(this+": error while listening :" + e);                if(owner!=null){                 owner.downlinkError();                }            }        }    }