MaxBatchByteSize takes the passed value read from the cluster setting and returns it unless the testing metamorphic value overrides it.

MaxBatchSize returns the max number of entries in the KV batch for a mutation operation (delete, insert, update, upsert) - including secondary index updates, FK cascading updates, etc - before the current KV batch is executed and a new batch is started.

ResetMaxBatchSizeForTests resets the maxBatchSize variable to the default mutation batch size.

SetMaxBatchSizeForTests modifies maxBatchSize variable.