anchor.diff:  @patch
   _registerExtension(String method, ServiceExtensionHandler handler) {
     _extensions[method] = handler;
  +  JS('', 'console.debug("dart.developer.registerExtension", #)', method);
   }
   
   @patch
   void _postEvent(String eventKind, String eventData) {
  -  // TODO.
  +  JS('', 'console.debug("dart.developer.postEvent", #, #)', eventKind,
  +      eventData);
   }
   
   @patch
  
positive.code: 
  @patch
  Object inspect(Object object) {
    return object;
  }
  
  
negative.code:     Zone zone,
      Object error,
      StackTrace stackTrace}) {
    Object items =
        JS('!', '{ message: #, name: #, level: # }', message, name, level);
    if (time != null) JS('', '#.time = #', items, time);
    if (sequenceNumber != null) {
      JS('', '#.sequenceNumber = #', items, sequenceNumber);
    }
    if (zone != null) JS('', '#.zone = #', items, zone);
    if (error != null) JS('', '#.error = #', items, error);
    if (stackTrace != null) JS('', '#.stackTrace = #', items, stackTrace);
  
    JS('', 'console.debug("dart.developer.log", #)', items);
  }
  
  final _extensions = Map<String, ServiceExtensionHandler>();
  