func (l *LocalMode) Unpack(token string) (data, footer []byte, err error) {
	return Decrypt(l.aead, token)
}
Unpack decrypt the token and return the plain data and optional footer.
package paseto
import (
	"crypto/cipher"
	"golang.org/x/crypto/chacha20poly1305"
)
type LocalMode struct {
	aead cipher.AEAD
}
func NewLocalMode(key []byte) (local *LocalMode, err error) {
	local = &LocalMode{}
	local.aead, err = chacha20poly1305.NewX(key)
	if err != nil {
		return nil, err
	}
	return local, nil
}
func (l *LocalMode) Pack(data, footer []byte) (token string, err error) {
	return Encrypt(l.aead, data, footer)
}