code: func brToString(b []byte) string {
  	if b == nil {
  		return "nil"
  	} else {
  		var buf bytes.Buffer
  		buf.WriteString("[")
  		for i, v := range b {
  			if i > 0 {
  				buf.WriteString(" ")
  			}
  			fmt.Fprintf(&buf, "%x", v)
  		}
  		buf.WriteString("]")
  		return fmt.Sprintf("%v %v", utf8ToString(b), buf.String())
  	}
  }
docs: // for debugging