对于嵌套在struct中的接口，如何在同一级别显示json？

type User struct {
    Name     string `json:"name"`
    Age      int    `json:"age"`
    Address  string `json:"address,omitempty"`
    Password string `json:"-"`
}

type User struct {
    Name     string `json:"name"`
    Age      int    `json:"age"`
    Address  Address `json:"address"`
}

type Address struct {
    City    string `json:"city"`
    Country string `json:"country"`
}

user := User{
    Name: "John",
    Age:  30,
    Address: Address{
        City:    "New York",
        Country: "USA",
    },
}

jsonData, err := json.Marshal(user)
if err != nil {
    fmt.Println("JSON encoding failed:", err)
    return
}

fmt.Println(string(jsonData))

{"name":"John","age":30,"address":{"city":"New York","country":"USA"}}