private static int compareRevisions(@Nullable ContentRevision bRev1, @Nullable ContentRevision bRev2) {
      if (bRev1 == null && bRev2 == null) return 0;
      if (bRev1 == null) return -1;
      if (bRev2 == null) return 1;
      String path1 = bRev1.getFile().getPath();
      String path2 = bRev2.getFile().getPath();
      return path1.compareTo(path2);
    }
private static int compareRevisions(@Nullable ContentRevision bRev1, @Nullable ContentRevision bRev2)