types.go
func capitalize(s string) string {
	r, l := utf8.DecodeRuneInString(s)
	b := make([]byte, l)
	utf8.EncodeRune(b, unicode.ToTitle(r))
	return strings.Join([]string{string(b), s[l:]}, "")
}
func capitalize(s string) string {
	r, l := utf8.DecodeRuneInString(s)
	b := make([]byte, l)
	utf8.EncodeRune(b, unicode.ToTitle(r))
	return strings.Join([]string{string(b), s[l:]}, "")
}
// capitalize the first letter in s