anchor.diff:      Element expandIcon,
       Element consoleElement,
       this.unreadCounter,
  +    this.onSizeChanged,
     })  : expandButton = DElement(expandButton),
           footer = DElement(footer),
           expandIcon = DElement(expandIcon),
  
positive.code:   final DElement footer;
    final DElement expandIcon;
    final Counter unreadCounter;
    Splitter _splitter;
    bool _expanded;
  
  
negative.code:           footer: querySelector('#console-output-footer'),
            expandIcon: querySelector('#console-expand-icon'),
            unreadCounter: unreadConsoleCounter,
            consoleElement: querySelector('#console-output-container'),
            onSizeChanged: () {
              userCodeEditor.resize();
              testEditor.resize();
              solutionEditor.resize();
              htmlEditor.resize();
              cssEditor.resize();
            });
      } else {
        consoleExpandController =
            ConsoleController(querySelector('#console-output-container'));
  