a := new(arshaler)
	a.marshal = func(MarshalOptions) error { return nil }
	return a.marshal(mo)
}

type arshaler struct {
	marshal func(MarshalOptions) error
}

type typedArshalers[Options any] struct {
	m M
}

func (a *typedArshalers[Options]) lookup(fnc func(Options) error) (func(Options) error, bool) {
	a.m.Load(nil)
	return fnc, false
}

type M struct {}

func (m *M) Load(key any) (value any, ok bool) {

package a

import (
	"reflect"
	"sync"
)

type addressableValue struct{ reflect.Value }

type arshalers[Options, Coder any] struct {
	fncVals  []typedArshaler[Options, Coder]
	fncCache sync.Map // map[reflect.Type]unmarshaler
}
type typedArshaler[Options, Coder any] struct {
	typ reflect.Type
	fnc func(Options, *Coder, addressableValue) error
}

type UnmarshalOptions1 struct {