anchor.diff:    /// reflected in [this]. If [base] is already a `List<E>`, it's returned
     /// unmodified.
     static List/*<E>*/ typed/*<E>*/(List base) =>
  -      base is List/*<E>*/ ? base : new TypedList/*<E>*/(base);
  +      base is List/*<E>*/ ? base : new TypeSafeList/*<E>*/(base);
   
     List<E> get _listBase => _base;
   
  
positive.code:   /// reflected in [this]. If [base] is already a `Map<K, V>`, it's returned
    /// unmodified.
    static Map/*<K, V>*/ typed/*<K, V>*/(Map base) =>
        base is Map<K, V> ? base : new TypedMap<K, V>(base);
  
    V operator [](Object key) => _base[key];
  
  
negative.code:   /// reflected in [this]. If [base] is already a `Queue<E>`, it's returned
    /// unmodified.
    static Queue/*<E>*/ typed/*<E>*/(Queue base) =>
        base is Queue/*<E>*/ ? base : new TypeSafeQueue/*<E>*/(base);
  
    Queue<E> get _baseQueue => _base;
  
  