package main

import (
	"encoding/json"
	"fmt"
)

type Object [3]byte

func (o Object) UnmarshalText(text []byte) error {
	return nil
}

func main() {
	const jsonStr = `{"foo": "foo"}`
	vals := map[string]Object{}
	if err := json.Unmarshal([]byte(jsonStr), &vals); err != nil {
		panic(err)
	}
	fmt.Printf("%#v\n", vals["foo"])
}