anchor.diff:     * compact_vm_config), can safely override this method to avoid printing extra
      * mesages in the console.
      */
  +  // TODO(sigmund): find a way to unify notifyController and _postMessage
     void notifyController(String message) {
  +  }
  +
  +  _postMessage(String message) {
       // In dart2js browser tests, the JavaScript-based test controller
       // intercepts calls to print and listens for "secret" messages.
       print(message);
  
positive.code:    */
    void onInit() {
      _receivePort = new ReceivePort();
      notifyController('unittest-suite-wait-for-done');
    }
  
    /** Called as soon as the unittest framework starts running. */
  
negative.code:    */
    void onDone(bool success) {
      if (success) {
        _postMessage('unittest-suite-success');
        _receivePort.close();
      } else {
        _receivePort.close();
  