anchor.diff:      _allowLeaveFutures.add(allow);
     }
   
  -  RouteEvent _clone() => new RouteEvent(path, parameters);
  +  RouteEvent _clone() => new RouteEvent(path, parameters, route);
   }
   
   abstract class Routable {
  
positive.code: class RouteEvent {
    final String path;
    final Map parameters;
    var _allowLeaveFutures = <Future<bool>>[];
  
    RouteEvent(this.path, this.parameters);
  
    /**
     * Can be called on leave with the future which will complete with a boolean
  
negative.code:         return _processNewRoute(baseRoute, path, match, matchedRoute);
        } else {
          baseRoute._currentRoute._lastEvent =
              new RouteEvent(match.match, match.parameters,
                  baseRoute._currentRoute);
          return route(match.tail, startingFrom: matchedRoute);
        }
      }
  