Bagaimanakah rangka kerja golang mengurus sesi dan keadaan pengguna?

import (
    "net/http"
)

func SetSession(w http.ResponseWriter, r *http.Request) {
    session, _ := r.Cookie("session")
    if session == nil {
        session = &http.Cookie{
            Name:  "session",
            Value: uuid.New().String(),
        }
        http.SetCookie(w, session)
    }
}

import (
    "sync"
)

var userState = &sync.Map{}

func SetUserState(w http.ResponseWriter, r *http.Request, key, value string) {
    session, _ := r.Cookie("session")
    userState.Store(session.Value, value)
}

import (
    "github.com/gorilla/sessions"
    "sync"
)

var store = sessions.NewCookieStore([]byte("secret-key"))
var userState = &sync.Map{}

func main() {
    http.HandleFunc("/", indexHandler)
    http.HandleFunc("/set-state", setStateHandler)
    http.ListenAndServe(":8080", nil)
}

func indexHandler(w http.ResponseWriter, r *http.Request) {
    session, _ := store.Get(r, "session")
    state, _ := userState.Load(session.Values["id"])
    if state != nil {
        fmt.Fprintf(w, "Your state is: %s", state)
    } else {
        fmt.Fprintf(w, "No state found")
    }
}

func setStateHandler(w http.ResponseWriter, r *http.Request) {
    session, _ := store.Get(r, "session")
    userState.Store(session.Values["id"], r.FormValue("state"))
    http.Redirect(w, r, "/", http.StatusFound)
}