anchor.diff:        if (resp is Future) {
           resp.then((r) {
             if (!completer.isCompleted) {
  -            completer.complete(r);
  +            _commitResponse(r, completer);
             }
           });
         } else {
           if (!completer.isCompleted) {
  -          completer.complete(resp);
  +          _commitResponse(resp, completer);
           }
         }
       }, onError: (e, s) {
  
positive.code:            stack: s, req: request)
               .then((_) {
                 if (!completer.isCompleted) {
                  completer.complete(response);
                 }
               });
        }
  
negative.code:     return completer.future;
    };
  };
  
  void _commitResponse(shelf.Response resp, Completer completer) {
    if (!resp.headers.containsKey(HttpHeaders.SERVER)) {
      resp = resp.change(headers: const {HttpHeaders.SERVER: "dart:io with Redstone.dart/Shelf"});
    }
    completer.complete(resp);
  }
  
  final Set<Symbol> _blacklistSet = _buildBlacklistSet();
  
  