security/nonce.go
func Getter(g NonceGetter) Option {
	return Option{func(o *options) {
		o.getter = g
	}}
}
func Getter(g NonceGetter) Option {
	return Option{func(o *options) {
		o.getter = g
	}}
}
// Getter allows the user to set the method by which a nonce is retrieved from
// the incoming request.