anchor.diff:  part of dart_flex;
  +
  +typedef String TitleHandler(String S);
    
   class RichText extends UIWrapper {
    
  
positive.code:     if (_richText != null) {
        _label.setInnerHtml(newText, treeSanitizer: new NullTreeSanitizer());
        
        control.title = newText.replaceAll(new RegExp(r'<[^>]+>'), '');
      } else _label.text = control.title = newText;
    }
  }
negative.code:       notify(
          new FrameworkEvent(
            'autoTruncateChangedEvent'
          )
        );
   
        _commitTextAutoTruncate();
      }
    }
    
    //---------------------------------
    // titleHandler
    //---------------------------------
   
    static const EventHook<FrameworkEvent> onTitleHandlerChangedEvent = const EventHook<FrameworkEvent>('titleHandlerChangedEvent');
    Stream<FrameworkEvent> get onTitleHandlerChanged => RichText.onTitleHandlerChangedEvent.forTarget(this);
    TitleHandler _titleHandler;
   
    TitleHandler get titleHandler => _titleHandler;
    set titleHandler(TitleHandler value) {
      if (value != _titleHandler) {
         _titleHandler = value;
   
        notify(
          new FrameworkEvent(
            'titleHandlerChangedEvent'
          )
        );
   
  