code: func (t *Throttler) BatchStartIndex() int {
  	return int(atomic.LoadInt32(&t.jobsStarted) * atomic.LoadInt32(&t.batchSize))
  }
docs: // BatchStartIndex returns the starting index for the next batch. The job count isn't modified
  // until th.Throttle() is called, so if you don't call Throttle before executing this
  // again, it will return the same index as before