anchor.diff:    }
   
     Future<ServiceActionEvent> _handleMessage(ServiceActionEvent event) {
  +    /*%TRACE3*/ print("(4> 2/13/14): _handleMessage!"); // TRACE%
       Completer<ServiceActionEvent> completer =
           new Completer<ServiceActionEvent>();
   
       ServiceImpl service = getService(event.serviceId);
  +    /*%TRACE3*/ print("""(4> 2/13/14): event.serviceId: ${event.serviceId}"""); // TRACE%
  +    /*%TRACE3*/ print("""(4> 2/13/14): service: ${service}"""); // TRACE%
       service.handleEvent(event).then((ServiceActionEvent responseEvent){
         if (responseEvent != null) {
           _sendResponse(responseEvent);
  +        /*%TRACE3*/ print("""(4> 2/13/14): completer: ${completer}"""); // TRACE%
           completer.complete();
         }
       });
  +    /*%TRACE3*/ print("""(4> 2/13/14): completer.future: ${completer.future}"""); // TRACE%
       return completer.future;
     }
   
  
positive.code:     _sendPort.send(receivePort.sendPort);
  
      receivePort.listen((arg) {
        try {
          if (arg is int) {
            _sendPort.send(arg);
          } else {
            ServiceActionEvent event = new ServiceActionEvent.fromMap(arg);
            if (event.response) {
              responseMessageController.add(event);
            } else {
              hostMessageController.add(event);
            }
          }
  
negative.code:   CompilerServiceImpl(ServicesIsolate isolate) : super(isolate);
  
    Future<ServiceActionEvent> handleEvent(ServiceActionEvent event) {
      /*%TRACE3*/ print("(4> 2/13/14): handleEvent!"); // TRACE%
      switch (event.actionId) {
        case "start":
          return Compiler.createCompiler().then((Compiler newCompler) {
  