anchor.diff:    }
   
     void _handleMarkerChange(workspace.MarkerChangeEvent event) {
  -    /*%TRACE3*/ print("(4> 2/1/14): _handleMarkerChange!"); // TRACE%
       if (event.hasChangesFor(currentFile)) {
         setMarkers(currentFile.getMarkers());
       }
  
positive.code: 
    ace.EditSession get currentSession => _aceEditor.session;
  
    // TODO(ericarnold): Deleteme.  testing
    static Map<ace.EditSession, String> filenameBySession = {};
  
    void switchTo(ace.EditSession session, [workspace.File file]) {
      if (_foldListenerSubscription != null) {
        _foldListenerSubscription.cancel();
  
negative.code:       _aceEditor.session = ace.createEditSession('', new ace.Mode('ace/mode/text'));
        _aceEditor.readOnly = true;
      } else {
        _aceEditor.session = session;
  
        if (_aceEditor.readOnly) {
  