Why call the `hessian.RegisterPOJO(&User{})` twice

[walkerxiong]

I have a doubt, why the function is called twice in the go-server pkg, is it necessary ? for example: helloworld/go-server/cmd/server.go

func main() {
>   hessian.RegisterPOJO(&pkg.User{})
    config.Load()

    initSignal()
}

but in the helloworld/pkg/user.go

func init() {
    config.SetProviderService(new(UserProvider))
    // ------for hessian2------
>   hessian.RegisterPOJO(&User{})
}

[AlexStocks]

It's a wrong guide. we should improve it.