@Nullable
  private static Long getRevisionTimestamp(@NotNull ContentRevision revision) {
    if (revision instanceof CurrentContentRevision) {
      try {
        FilePath filePath = revision.getFile();
        Path path = filePath.getIOFile().toPath();
        return Files.getLastModifiedTime(path).toMillis();
      }
      catch (IOException e) {
        return null;
      }
    }
    return null;
  }
@Nullable
  private static Long getRevisionTimestamp(@NotNull ContentRevision revision)