anchor.diff:  }
   
   class SparkPolymer extends Spark {
  -  List<String> _themes = [
  -    ace.Theme.AMBIANCE,
  -    ace.Theme.MONOKAI,
  -    ace.Theme.PASTEL_ON_DARK,
  -    ace.Theme.TEXTMATE,
  -  ];
  -
     SparkPolymer() : super();
   
     @override
     void setupEditorThemes() {
       syncPrefs.getValue('aceTheme').then((String theme) {
  -      final int selected = (theme != null) ? _themes.indexOf(theme) : 0;
  +      final selected = (theme != null) ? AceEditor.THEMES.indexOf(theme) : 0;
   
         (querySelector('#themeChooser') as dynamic)
  -        ..items = _themes.map(_beautifyThemeName)
  +        ..items = AceEditor.THEMES.map(_beautifyThemeName)
           ..selected = selected
           ..onClick.listen(_switchTheme);
         _switchTheme();
  
positive.code: 
  import 'dart:html';
  import 'package:polymer/polymer.dart' as polymer;
  import 'package:ace/ace.dart' as ace;
  
  import 'spark.dart';
  import 'lib/utils.dart' as utils;
  
  void main() {
  
negative.code:         (querySelector('#themeChooser') as dynamic).selected;
      if (selected == -1)
        selected = 0;
      final String themeName = AceEditor.THEMES[selected];
      editor.theme = themeName;
      syncPrefs.setValue('aceTheme', themeName);
    }
  
    String _beautifyThemeName(String themeName) =>
        utils.capitalize(themeName).replaceAll('_', ' ');
  }
  