Trace_collection.Make_statSourceMake state trace collector.
module Store : Irmin.Generic_key.KVtype t = {writer : Def.writer;store_path : string;mutable t0 : Mtime_clock.counter;mutable prev_merge_durations : float list;mutable commit_before : Def.bag_of_stats * Def.store_before;}Imperative stat trace collector. It is optimised to minimise the CPU footprint.