anchor.diff:     * Check the files on disk for changes that we don't know about. Fire resource
      * change events as necessary.
      */
  -  void refresh() {
  -    // TODO: Implement.
  -
  -    print('Project.refresh(): ${name}');
  +  Future refresh() {
  +    workspace.pauseResourceEvents();
  +
  +    return _refresh().whenComplete(() {
  +      workspace.resumeResourceEvents();
  +    });
     }
   }
   
  
positive.code:   void _removeChild(Resource resource, {bool fireEvent: true}) {
      _localChildren.remove(resource);
      if (fireEvent) {
        _fireResourceEvent(new ResourceChangeEvent.fromSingle(
            new ChangeDelta(resource, EventType.DELETE)));
      }
    }
  
  
negative.code:  * files that it contains are loose files; they do not have parent projects.
   */
  class Workspace implements Container {
    int _resourcePauseCount = 0;
    List<ChangeDelta> _resourceChangeList = [];
  
    int _markersPauseCount = 0;
    List<MarkerDelta> _makerChangeList = [];
  
  