public static byte @Nullable [] getLastUnchangedContent(@NotNull VirtualFile file) {
    final Integer id = getSavedContentId(file);
    try {
      return id == null ? null : getFS().contentsToByteArray(id);
    }
    catch (IOException e) {
      LOG.info(e);
    }
    return null;
  }
public static byte @Nullable [] getLastUnchangedContent(@NotNull VirtualFile file)