在以下代码中，如何在Web视图中调用函数doSomething？我希望可以在JavaScript中执行以下操作：window.external.doSomething()

package main

import "github.com/zserge/webview"

func doSomething() {
    //Some Go code goes here. Maybe to write to the file system or something
}

func main() {
    // Open wikipedia in a 800x600 resizable window
    webview.Open("Desktop App Demo","http://mywebapp.com/somepage/",800,600,true)
}