code: func isPrintable(s string) bool {
  	if !utf8.ValidString(s) {
  		return false
  	}
  	for _, ch := range s {
  		if !unicode.IsPrint(ch) {
  			return false
  		}
  	}
  	return true
  }
docs: // isPrintable returns true if the string is valid unicode and contains only printable runes.