function missmatch if function name duplicated

[jarlyyn]

package main

import (
	"fmt"

	"github.com/dop251/goja"
)

var js = `
function a(){}
function b(){ return "b" }
function c(){ return "c" }
function a(){}
`

func main() {
	vm := goja.New()
	_, err := vm.RunString(js)
	if err != nil {
		panic(err)
	}
	val, err := vm.RunString("b()")
	if err != nil {
		panic(err)
	}
	fmt.Println(val.String())

}

I think this code should panic or print string "b",but string "c" printed.