anchor.diff:      EventEmitter removeListener(event, listener) {
           if (_listeners.containsKey(event) && _listeners[event].contains(listener)) {
               _listeners[event].remove(listener);
  -            emit('removeListener', [event, listener]);
  +            emit(_REMOVE_LISTENER_EVENT_NAME, [event, listener]);
           }
   
           if (_oneTimeListeners.containsKey(event) && _oneTimeListeners[event].contains(listener)) {
               _oneTimeListeners[event].remove(listener);
  -            emit('removeListener', [event, listener]);
  +            emit(_REMOVE_LISTENER_EVENT_NAME, [event, listener]);
           }
   
           return this;
  
positive.code:         _verifyListenersLimit(event);
          _oneTimeListeners[event].add(listener);
  
          emit('newListener', [event, listener]);
  
          return this;
      }
  
negative.code:     static int defaultMaxListeners = 10;
      int _maxListeners;
  
      static const String _NEW_LISTENER_EVENT_NAME = 'newListener';
      static const String _REMOVE_LISTENER_EVENT_NAME = 'removeListener';
  
      EventEmitter addListener(event, listener) {
          if (!_listeners.containsKey(event)) {
              _listeners[event] = [];
  