anchor.diff:  
   /** Advance to the next test case. */
   void _nextTestCase() {
  -  _defer(() {
  +  runAsync(() {
       _currentTestCaseIndex++;
       _nextBatch();
     });
  
positive.code:   if (configAutoStart && _config.autoStart) {
      // Immediately queue the suite up. It will run after a timeout (i.e. after
      // main() has returned).
      _defer(runTests);
    }
  }
  
  
negative.code: 
    _config.onStart();
  
    runAsync(() {
      _nextBatch();
    });
  }
  