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