More commenting for something different!

Questions I've come across whilst commenting:

RaceContestant:
1. do we need start/finishRace methods if we're using
setStart/FinishTimes methods (even in RaceCarnival)?

RaceCarnival:
1. should we have an addCategory method?
2. add validation on the addRaceContestant method if the RaceContestant
has an existing category (otherwise don't add)?
3. is showRaceResults a redundant method?
4. does searchByName need finishing?
5. add toString method?