anchor.diff:            ++_callbackFunctionsOutstanding;
             return testFunction();
           })
  -        .catchError(errorHandler('Test'))
  +        .catchError(_errorHandler('Test'))
           .then((_) {
             _markCallbackComplete();
             if (result == null) {
  
positive.code: 
    bool get isComplete => !enabled || result != null;
  
    errorHandler(stage) => (e) {
      var stack = getAttachedStackTrace(e);
      if (result == null || result == PASS) {
        if (e is TestFailure) {
  
negative.code:               if (tearDown != null) {
                  return tearDown();
                }
              }).catchError(_errorHandler('Teardown'));
            } else if (tearDown != null) {
              return tearDown();
            }
          })
          .catchError(_errorHandler('Teardown'));
    }
  
    // Set the results, notify the config, and return true if this
  