code: func (r *responseStats) update(rsp libhoney.Response) {
  	r.lock.Lock()
  	defer r.lock.Unlock()
  	r.count += 1
  	r.statusCodes[rsp.StatusCode] += 1
  	r.bodies[strings.TrimSpace(string(rsp.Body))] += 1
  	if rsp.Err != nil {
  		r.errors[rsp.Err.Error()] += 1
  	}
  	if r.minDuration == 0 {
  		r.minDuration = rsp.Duration
  	}
  	if rsp.Duration < r.minDuration {
  		r.minDuration = rsp.Duration
  	} else if rsp.Duration > r.maxDuration {
  		r.maxDuration = rsp.Duration
  	}
  	r.sumDuration += rsp.Duration
  	ev := rsp.Metadata.(event.Event)
  	r.event = &ev
  }
docs: // update adds a response into the stats container