CheckAndRecordBodyHash checks the current message's body hash against all the body hashes we've seen, to prevent replays.

CheckAndRecordPrevPointer checks the current message's header hash against all the prev pointers we've ever seen.

InsatiableResultCollector aggregates all messages all the way back.

Keeps map counting emoji used in reactions for each user.

If the user has less than 5 favorite reacjis we stuff these defaults in.

SimpleResultCollector aggregates all results in a basic way.

TypedResultCollector aggregates results with a type constraints.