code: func parseCapacity(b []byte, r *regexp.Regexp) (uint64, error) {
  	matches := r.FindSubmatch(b)
  	if len(matches) != 2 {
  		return 0, fmt.Errorf("failed to match regexp in output: %q", string(b))
  	}
  	m, err := strconv.ParseUint(string(matches[1]), 10, 64)
  	if err != nil {
  		return 0, err
  	}
  
  	// Convert to bytes.
  	return m * 1024, err
  }
docs: // parseCapacity matches a Regexp in a []byte, returning the resulting value in bytes.
  // Assumes that the value matched by the Regexp is in KB.