More powerful than a “fuzzing” test io would be a deterministic test io. I.e., one you can tick forward the various concurrent branches deterministically to pro

More powerful than a “fuzzing” test io would be a deterministic test io. I.e., one you can tick forward the various concurrent branches deterministically to prove that various races are safely handled. This makes it possible to capture all those “what if thread A executes this line first then B is executed” etc. Something that is missing in most concurrent frameworks.