code: func NewProgressReader(in io.ReadCloser, out Output, size int64, id, action string) *Reader {
  	return &Reader{
  		in:          in,
  		out:         out,
  		size:        size,
  		id:          id,
  		action:      action,
  		rateLimiter: rate.NewLimiter(rate.Every(100*time.Millisecond), 1),
  	}
  }
docs: // NewProgressReader creates a new ProgressReader.