@Override
 public void leave(final AOObject obj, final Region region) {
   final Message message = this.makeMessage(obj, region);
   if (message == null) {
     Log.error(
         "MessageRegionTrigger: can't build message for " + obj + " leaving region " + region);
     return;
   }
   this.configureMessage(message, obj, region, "onLeave");
   Engine.getAgent().sendBroadcast(message);
 }