anchor.diff:             stack: s, req: request)
                .then((_) {
                  if (!completer.isCompleted) {
  -                completer.complete(response);
  +                _commitResponse(response, completer);
                  }
                });
         }
  
positive.code:     return completer.future;
    };
  };
  
  final Set<Symbol> _blacklistSet = _buildBlacklistSet();
  
  
negative.code:       if (resp is Future) {
          resp.then((r) {
            if (!completer.isCompleted) {
              _commitResponse(r, completer);
            }
          });
        } else {
          if (!completer.isCompleted) {
            _commitResponse(resp, completer);
          }
        }
      }, onError: (e, s) {
  