anchor.diff:      actionManager.registerAction(new FileExitAction(this));
       actionManager.registerAction(new FileDeleteAction(this));
       actionManager.registerAction(new FileCloseAction(this));
  -    actionManager.registerAction(new ProjectOpenAction(this));
  +    actionManager.registerAction(new FolderOpenAction(this));
       actionManager.registerAction(new RunTestsAction(this));
       actionManager.registerAction(new AboutSparkAction(this));
       actionManager.registerKeyListener();
  
positive.code:     }).catchError((e) => null);
    }
  
    void openProject() {
      chrome.ChooseEntryOptions options = new chrome.ChooseEntryOptions(
          type: chrome.ChooseEntryType.OPEN_DIRECTORY);
      chrome.fileSystem.chooseEntry(options).then((chrome.ChooseEntryResult result) {
  
negative.code:   }
  }
  
  class FolderOpenAction extends SparkAction {
    FolderOpenAction(Spark spark) : super(spark, "folder-open", "Open Folder...");
  
    void _invoke([Object context]) => spark.openFolder();
  }
  
  class AboutSparkAction extends SparkAction {
  