问如何在golang中实现void*？

EN

package main

import (
    "fmt"
)

type Node struct {
    List []*Node
    Data interface{}
}

func main() {
    trivial := Node{}

    leaf := Node{Data: 1}

    tree := Node{
        List: []*Node{
            &leaf,
            &leaf,
        },
    }
    out(trivial)
    out(leaf)
    out(tree)
}

func out(x interface{}) {
    fmt.Printf("%T:%+v\n", x, x)
}

// main.Node:{List:[] Data:<nil>}
// main.Node:{List:[] Data:1}
// main.Node:{List:[0xc82000e180 0xc82000e180] Data:<nil>}