如何在 Gin 中有效地將路由分組，以實現更好的程式碼組織和可維護性？

<code class="go">v1 := router.Group("/v1")
{
  v1.Group("users", usersRoutes)
  v1.Group("pictures", picturesRoutes)
  v1.Group("friends", friendsRoutes)
}</code>

<code class="go">package app

import (
    "github.com/gin-gonic/gin"
)

// Defining the routes structure
type routes struct {
    router *gin.Engine
}

// NewRoutes initializes a new route struct
func NewRoutes() routes {
    r := routes{
        router: gin.Default(),
    }
    
    // Group routes under the "/v1" version
    v1 := r.router.Group("/v1")
    
    // Define handlers for ping and users routes in separate functions
    r.addPing(v1)
    r.addUsers(v1)
    
    return r
}

// Run starts the web server
func (r routes) Run(addr ...string) error {
    return r.router.Run()
}

// addPing adds routes for ping
func (r routes) addPing(rg *gin.RouterGroup) {
    ping := rg.Group("/ping")
    ping.GET("/", pongFunction)
}

// addUsers adds routes for users
func (r routes) addUsers(rg *gin.RouterGroup) {
    users := rg.Group("/users")
    users.GET("/", getUsersFunction)
}</code>