杜松子酒框架gin.Context.Param（）提供错误的值

Question

Here is simple code that i am trying

package main

import (
    "log"

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

func main() {
    server := gin.Default()

    server.GET("/countries/*code", GetCountries)
    server.Run()
}

func GetCountries(c *gin.Context) {
    ccode := c.Param("code")
    log.Printf("Code: %s", ccode)
}

I have extracted code from url and log it. Here is output after running and accessing urls

[GIN-debug] redirecting request 301: /countries --> /countries/
Code: /
[GIN] 2016/07/16 - 17:24:59 | 200 |      16.508��s | ::1 |   GET     /countries/
Code: /USA
[GIN] 2016/07/16 - 17:25:17 | 200 |       12.47��s | ::1 |   GET     /countries/USA

In output, you can see, it is giving code along with the "/". If there is no code in url still it is giving "/"

Is it a bug or expected behaviour of gin? Do i need to check for "/" to know whether code is actually passed or not?