You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: message_test.go
    path of file: ./repos/lotus/chain/types
    
    the code of the file until where you have to start completion: // stm: #unit
package types

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/stretchr/testify/require"

	"github.com/filecoin-projec
    
func TestMessageJson(t *testing.T) {
	m := &Message{
		To:    builtin2.StoragePowerActorAddr,
		From:  builtin2.SystemActorAddr,
		Nonce: 34,
		Value: big.Zero(),

		GasLimit:   123,
		GasFeeCap:  big.NewInt(234),
		GasPremium: big.NewInt(234),

		Method: 6,
		Params: []byte("hai"),
	}

	b, err := json.Marshal(m)
	require.NoError(t, err)

	exp := []byte("{\"Version\":0,\"To\":\"f04\",\"From\":\"f00\",\"Nonce\":34,\"Value\":\"0\",\"GasLimit\":123,\"GasFeeCap\":\"234\",\"GasPremium\":\"234\",\"Method\":6,\"Params\":\"aGFp\",\"CID\":{\"/\":\"bafy2bzaced5rdpz57e64sc7mdwjn3blicglhpialnrph2dlbufhf6iha63dmc\"}}")
	fmt.Println(string(b))

	//stm: @TYPES_MESSAGE_JSON_EQUAL_CALL_001
	require.Equal(t, exp, b)

	var um Message
	require.NoError(t, json.Unmarshal(b, &um))

	//stm: @TYPES_MESSAGE_JSON_EQUAL_CALL_002
	require.EqualValues(t, *m, um)
}