synchronized (lock) {
    public void processNextTickEvent() {        org.cougaar.core.qos.frame.visualizer.event.TickEvent tickEvent=null;        synchronized (lock) {            if (tickEventQueue.size() > 0) {                tickEvent = (TickEvent)tickEventQueue.get(0);                tickEventQueue.remove(0);            }        }        if (tickEvent == null)            return;        processingTickEvent = true;        if (log.isDebugEnabled())            log.debug("processing "+tickEvent);        transitions.addAll(tickEvent.getTransitions());    }