anchor.diff:  
     void onTestStart(TestCase test) {
       super.onTestStart(test);
  -    _progressLine(_start, _pass, _fail, test.description);
  +    _progressLine(test.description);
     }
   
     void onTestResult(TestCase test) {
       super.onTestResult(test);
       if (test.result == PASS) {
  -      _pass++;
  -      _progressLine(_start, _pass, _fail, test.description);
  +      _passing.add(test.id);
  +      _progressLine(test.description);
       } else {
  -      _fail++;
  -      _progressLine(_start, _pass, _fail, test.description);
  +      _failing.add(test.id);
  +      _progressLine(test.description);
         _print();
         if (test.message != '') {
           _print(indent(test.message));
  
positive.code:     if (passed == 0 && failed == 0 && errors == 0 && uncaughtError == null) {
        _print('\nNo tests ran.');
      } else if (failed == 0 && errors == 0 && uncaughtError == null) {
        _progressLine(_start, _pass, _fail, 'All tests passed!', _NONE);
        _print();
        success = true;
      } else {
        _progressLine(_start, _pass, _fail, 'Some tests failed.', _RED);
        _print();
        if (uncaughtError != null) {
          _print('Top-level uncaught error: $uncaughtError');
  
negative.code: 
    final int _nonVisiblePrefix = 1 + _GREEN.length + _NONE.length;
  
    void _progressLine(String message, [String color = _NONE]) {
      var duration = (new DateTime.now()).difference(_start);
      var buffer = new StringBuffer();
      // \r moves back to the beginning of the current line.
      buffer.write('\r${_timeString(duration)} ');
      buffer.write(_GREEN);
      buffer.write('+');
      buffer.write(_pass);
      buffer.write(_NONE);
      if (_fail != 0) {
        buffer.write(_RED);
        buffer.write(' -');
        buffer.write(_fail);
        buffer.write(_NONE);
      }
      buffer.write(': ');
  