@Nullable
    File getFile(String id) {
      if (myRootType.isHidden()) return null;
      String rootPath = ScratchFileService.getInstance().getRootPath(HistoryRootType.getInstance());
      return new File(FileUtil.toSystemDependentName(rootPath + "/" + getHistoryName(myRootType, myFileExtension, id)));
    }
@Nullable
    File getFile(String id)