anchor.diff:  
       if (success) {
         _postMessage('unittest-suite-success');
  +      _receivePort.close();
       } else {
         throw new Exception('Some tests failed.');
       }
  
positive.code:  */
  
  class Configuration {
    TestCase currentTestCase = null;
  
    /**
  
negative.code:    * wait until they are done.
     */
    void onStart() {
      _receivePort = new ReceivePort();
      _postMessage('unittest-suite-wait-for-done');
    }
  
  