code: func (mc *MyCounter) Down(max int64, w io.Writer) error {
  	if max == 11 {
  		return fmt.Errorf("we don't *do* elevensies")
  	}
  	e := json.NewEncoder(w)
  	for ix := int64(0); ix <= max; ix++ {
  		r := max - ix
  		fmt.Printf("Iteration %d\n", r)
  		_ = e.Encode(models.Mark{Remains: &r})
  		if ix != max {
  			time.Sleep(1 * time.Second)
  		}
  	}
  	return nil
  }
docs: // Down is the concrete implementation that spits out the JSON bodies