@Nullable
  private static Date parseVersionAsDate(@NotNull String versionId) {
    try {
      Matcher tsMatcher = ourTsPattern.matcher(versionId);
      if (tsMatcher.find()) {
        long fromTsPattern = Long.parseLong(tsMatcher.group(1));
        return new Date(fromTsPattern);
      }
      else {
        return new Date(versionId);
      }
    }
    catch (IllegalArgumentException e) {
      return null;
    }
  }
@Nullable
  private static Date parseVersionAsDate(@NotNull String versionId)