code: func splitLength(s string, length int) []string {
  	var ret []string
  
  	for len(s) > 0 {
  		tmp := truncateString(s, length)
  		if len(tmp) == 0 {
  			// too short length, or invalid UTF-8 string
  			break
  		}
  		ret = append(ret, tmp)
  		s = s[len(tmp):]
  	}
  
  	return ret
  }
docs: // splitLength returns a slice of strings, each string is at most length bytes long.
  // Does not break UTF-8 codepoints.