anchor.diff:    /// Routes added reentrantly within [PointerRouter.route] will take effect when
     /// routing the next event.
     void addGlobalRoute(PointerRoute route, [Matrix4 transform]) {
  -    assert(!_globalRoutes.any(_RouteEntry.isRoutePredicate(route)));
  -    _globalRoutes.add(_RouteEntry(route: route, transform: transform));
  +    assert(!_globalRoutes.containsKey(route));
  +    _globalRoutes[route] = transform;
     }
   
     /// Removes a route from the global entry in the routing table.
  
positive.code: 
  /// A routing table for [PointerEvent] events.
  class PointerRouter {
    final Map<int, LinkedHashSet<_RouteEntry>> _routeMap = <int, LinkedHashSet<_RouteEntry>>{};
    final LinkedHashSet<_RouteEntry> _globalRoutes = LinkedHashSet<_RouteEntry>();
  
    /// Adds a route to the routing table.
    ///
  
negative.code: // Copyright 2015 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  import 'package:flutter/foundation.dart';
  import 'package:vector_math/vector_math_64.dart';
  