anchor.diff:      preserveMetadata();
       return _metadata.map(reflect).toList();
     }
  +
  +  // TODO(ahe): Implement these.
  +  DeclarationMirror get owner => throw new UnimplementedError();
  +  InstanceMirror invoke(Symbol memberName,
  +                        List positionalArguments,
  +                        [Map<Symbol,dynamic> namedArguments]) {
  +    throw new UnimplementedError();
  +  }
   }
   
   String n(Symbol symbol) => _symbol_dev.Symbol.getName(symbol);
  
positive.code:   }
  
    String toString() => "ClosureMirror on '${Error.safeToString(reflectee)}'";
  }
  
  class JsMethodMirror extends JsDeclarationMirror implements MethodMirror {
  
negative.code: 
    // TODO(ahe): Doesn't match the specification, see http://dartbug.com/11569.
    bool get isTopLevel => true;
  
    // TODO(ahe): Implement this.
    List<InstanceMirror> get metadata => throw new UnimplementedError();
  }
  
  class JsLibraryMirror extends JsDeclarationMirror with JsObjectMirror
  