[Golang]嵌套struct转换成json时丢失信息

package aaa

import (
"encoding/json"
"fmt"
)

type Person struct {
ID string
Name string
}

type Class struct {
ID string
Name string
stuff []Person
}

func Check() {

pa := Person{ID: "001", Name: "赵大"}
pb := Person{"002", "刘二"}
ca := Class{"001", "初一（3）班", []Person{pa, pb}}

fmt.Println(ca)

data, _ := json.MarshalIndent(ca, "", " ")

fmt.Printf("%s\n", data)

}