anchor.diff:   */
   
   class Configuration {
  +  // The VM won't shut down if a receive port is open. Use this to make sure
  +  // we correctly wait for asynchronous tests.
  +  ReceivePort _receivePort;
     TestCase currentTestCase = null;
   
     /**
  
positive.code: 
      if (success) {
        _postMessage('unittest-suite-success');
      } else {
        throw new Exception('Some tests failed.');
      }
  
negative.code:       String uncaughtError) {
      // Print each test's result.
      for (final t in _tests) {
        var resultString = "${t.result}".toUpperCase();
        print('$resultString: ${t.description}');
  
        if (t.message != '') {
          print(_indent(t.message));
  