anchor.diff:      return new Future.value(entry.fullPath);
     }
   
  -  Future restoreManager(Spark spark, String folderToken) =>
  -      throw "Can't restore mock manager";
  -
  -  Future<ProjectLocationManager> restoreMockManager(Spark spark) {
  +  Future<ProjectLocationManager> restoreManager(Spark spark, String folderToken) {
       return MockProjectLocationManager.restoreManager(spark)
           .then((ProjectLocationManager manager) {
             _locationManager = manager;
  
positive.code:    */
    static Future<ProjectLocationManager> restoreManager(Spark spark,
        String folderToken) {
      if (folderToken == null) {
        return new Future.value(new ProjectLocationManager._(spark));
      }
  
negative.code: void setMockFilesystemAccess() {
    // TODO(ericarnold): Assert something else about FSA
  //  assert(_fileSystemAccess == null);
    _fileSystemAccess = new MockFileSystemAccess();
  }
  
  FileSystemAccess get fileSystemAccess {
    if (_fileSystemAccess == null) {
      _fileSystemAccess = new FileSystemAccess._();
    }
  