Why do i convert map to json, map includes list values which is nothing after converting to json : func Test_JsonTtransfer(t *testing.T) {

	uid := "306"
	phoneList := list.New()
	phoneList.PushBack("18513622928")
	fmt.Println("phoneList=======", phoneList.Len())


	jsonPhoneList, err := json.Marshal(phoneList)
	if err != nil {
	    fmt.Println("error:", err)
	}
	fmt.Println("jsonPhoneList=======", string(jsonPhoneList))

	idCardList := list.New()
	idCardList.PushBack("230405197608040640")

	request := make(map[string]interface{})
	request["uid"] = uid

	request["phones"] = phoneList

	request["id_cards"] = idCardList

	json, err := json.Marshal(request)
	if err != nil {
	    fmt.Println("error:", err)
	}

	fmt.Println("json=======", json)
	fmt.Println("json=======", string(json))
}


output:

D:/Sys/server/Go\bin\go.exe test -v golang-test/com/http/test -run ^Test_JsonTtransfer$
phoneList======= 1
jsonPhoneList======= {}
json======= [123 34 105 100 95 99 97 114 100 115 34 58 123 125 44 34 112 104 111 110 101 115 34 58 123 125 44 34 117 105 100 34 58 34 51 48 54 34 125]
json======= {"id_cards":{},"phones":{},"uid":"306"}
ok  	golang-test/com/http/test	0.482s


phones should be list values, but nothing. help me 


