code: func StatsHandler(c context.Context) error {
  	masters, err := buildstore.AllMasters(c, false)
  	if err != nil {
  		return errors.Annotate(err, "failed to fetch masters").Err()
  	}
  	now := clock.Now(c)
  	for _, m := range masters {
  		allMasterTimer.Set(c, now.Sub(m.Modified).Seconds(), m.Name)
  	}
  	return nil
  }
docs: // StatsHandler is a cron endpoint that sends stats periodically.