anchor.diff:  
     String toString() {
       return "class $type:\n" +
  -        elements.fold("", (a, b) => a + b.toString() + "\n");
  +        elements.values.fold("", (a, b) => a + b.toString() + "\n");
     }
   }
   
  
positive.code: 
  class Element {
    final Type type;
  
    final Symbol symbol;
    final String key;
    bool isMap;
    bool isList;
    bool isPrimList;
    bool isPrimMap;
    Type listType;
  
    Element(this.key, this.symbol, this.type);
  
    bool get isComplex => !isPrimList && !isList && !isMap && !isPrimMap;
    @override
    String toString() {
      return "Element<$type> key: $key, symbol: $symbol, isMap: $isMap, isList: $isList";
    }
  }
  
  
negative.code:           element.isList = false;
            element.isPrimList = false;
          }
          elements[key] = element;
        }
      }
    });
  