alg.go
func (alg Algorithm) Encode(signer Signer, obj interface{}) ([]byte, error) {
	return Encode(alg, signer, obj)
}
func (alg Algorithm) Encode(signer Signer, obj interface{}) ([]byte, error) {
	return Encode(alg, signer, obj)
}
// Encode serializes a JWT using the Algorithm and Signer.