anchor.diff:      return this.count() + this._deletedCount;
     }
   
  -  // Add an object to the table and return an ID for serialization.
  +  // Adds an object to the table and return an ID for serialization.
     ProxiedReferenceTable.prototype.add = function (obj) {
       if (this.scopeIndices.length == 0) {
         throw "Cannot allocate a proxy outside of a scope.";
  
positive.code: })();
  """;
  
  // Inject JavaScript source code onto the page.
  // This is only used to load the bootstrapping code above.
  void _inject(code) {
    final script = new ScriptElement();
  
negative.code:   }
  
    /**
     * Constructs a [Proxy] to a new JavaScript map or list created defined via
     * Dart map or list.
     */
    factory Proxy._json(data) {
  