@Override
  public Callable<DiffElement<VirtualFile>> getElementChooser(final Project project) {
    return () -> {
      final FileChooserDescriptor descriptor = getChooserDescriptor();
      final VirtualFile[] result = FileChooser.chooseFiles(descriptor, project, getValue());
      return result.length == 1 ? createElement(result[0], myDiffRoot) : null;
    };
  }
@Override
  public Callable<DiffElement<VirtualFile>> getElementChooser(final Project project)