func (c CookieSigner) EncodeValue(value string) string {
	return fmt.Sprintf("%s.%s",
		base64.URLEncoding.EncodeToString(c.mac(value)),
		value)
}
func (c CookieSigner) EncodeValue(value string) string {
	return fmt.Sprintf("%s.%s",
		base64.URLEncoding.EncodeToString(c.mac(value)),
		value)
}
// EncodeValue signs and encodes a cookie value