anchor.diff:  class SparkPolymer extends Spark {
     SparkPolymerUI _ui;
   
  -  Future openFolder(chrome.DirectoryEntry entry) {
  +  Future<SparkJobStatus> openFolder(chrome.DirectoryEntry entry) {
       return _beforeSystemModal()
           .then((_) => super.openFolder(entry))
  -        .then((_) => _systemModalComplete())
  -        .catchError((e) => _systemModalComplete());
  +        .then((status) {
  +          _systemModalComplete();
  +          return status;
  +        }).catchError((e) => _systemModalComplete());
     }
   
     Future openFile() {
  
positive.code:         .catchError((e) => _systemModalComplete());
    }
  
    Future importFolder([List<ws.Resource> resources,
                         chrome.DirectoryEntry entry]) {
      return _beforeSystemModal()
          .then((_) => super.importFolder(resources, entry))
          .whenComplete(() => _systemModalComplete());
  
negative.code: import 'lib/jobs.dart';
  import 'lib/platform_info.dart';
  import 'lib/preferences.dart';
  import 'lib/status.dart';
  import 'lib/workspace.dart' as ws;
  
  class _TimeLogger {
  