last stable version
   at [1]https://lists.cpunks.org/pipermail/cypherpunks/2022-July/102291.h
   tml
   although there can be further optimization, I think it makes sense to
   move a little toward using it for me
   next step might be to change flushing so the index can be accumulated
   during writes or mini flushes, so as to be able to limit the total size
   of an index per flush if needed, without issue.
   makes sense to clean/reduce/remove the notes and assertions to ease
   copying algorithm to other languages etc

References

   1. https://lists.cpunks.org/pipermail/cypherpunks/2022-July/102291.html