anchor.diff:  
   serialization$uninitializedLateValue_ get serialization$uninitializedLateValue => $package$serialization$uninitializedLateValue;
   
  +class serialization$NativeDeque implements dart$$Basic {
  +    serialization$NativeDeque() {
  +        _$deque = new $dart$collection.DoubleLinkedQueue();
  +    }
  +    $dart$collection.DoubleLinkedQueue _$deque;
  +    void pushFront([$dart$core.Object element]) {
  +        _$deque.addFirst(element);
  +    }
  +    void pushBack([$dart$core.Object element]) {
  +        _$deque.addLast(element);
  +    }
  +    $dart$core.Object popFront() => _$deque.removeFirst();
  +    $dart$core.bool get empty => _$deque.isEmpty;
  +    $dart$core.String toString() => _$deque.toString();
  +}
  +class serialization$NativeMap implements dart$$Basic {
  +    serialization$NativeMap() {
  +        _$m = new $dart$core.Map();
  +    }
  +    $dart$core.Map _$m;
  +    void put([$dart$core.Object id, $dart$core.Object instanceOrPartial]) {
  +        _$m[id] = instanceOrPartial;
  +    }
  +    $dart$core.Object get([$dart$core.Object id]) => _$m[id];
  +    $dart$core.bool contains([$dart$core.Object id]) => _$m.containsKey(id);
  +    $dart$core.int get size => _$m.length;
  +    Iterable get items => new $ceylon$interop$dart.CeylonIterable(_$m.values);
  +    Iterable get keys => new $ceylon$interop$dart.CeylonIterable(_$m.keys);
  +    $dart$core.String toString() => _$m.toString();
  +}
   abstract class serialization$Outer implements serialization$ReachableReference {
       $dart$core.Object referred([$dart$core.Object instance]);
   }
  
positive.code:                 return $package$empty;
              }
          }
      }
  }
  abstract class serialization$ReachableReference {
  
negative.code: 
  impl$outerImpl_ get impl$outerImpl => $package$impl$outerImpl;
  
  class impl$reach_ implements dart$$Basic {
      impl$reach_() {}
      Iterator references([$dart$core.Object instance]) => $package$nothing as Iterator;
      $dart$core.Object getAnything([$dart$core.Object instance, serialization$ReachableReference ref]) => $package$nothing;
      $dart$core.Object getObject([$dart$core.Object instance, serialization$ReachableReference ref]) => $package$nothing;
      $dart$core.String toString() => "reach";
  }
  final impl$reach_ $package$impl$reach = new impl$reach_();
  
  impl$reach_ get impl$reach => $package$impl$reach;
  
  void $package$impl$$rethrow([Throwable x]) {
      throw x;
  }
  