从浏览器控制台JS调用类(在模块中定义)时,“Uncaught ReferenceError:…未定义”

            //implementation details
            const _stackCollection = new WeakMap();


            //interface
            export class Stack {

                constructor() {
                    _stackCollection.set(this, []);
                }

                get count() {
                    return _stackCollection.get(this).length;
                }

                pop() {
                    if (this.count === 0)
                        throw new Error('Nothing to pop');

                    return _stackCollection.get(this).pop();
                }

                peek() {
                    if (this.count === 0)
                        throw new Error('Nothing to peek');

                    return _stackCollection.get(this)[this.count - 1];
                }

                push(e) {
                    _stackCollection.get(this).push(e);
                    return;
                }

            }

导入给定类的模块如下所示 模块.js:

   import {Stack} from './class.js';

index.html如下所示:

    <!DOCTYPE html>
    <html lang="en">

    <head>
        <meta charset="UTF-8">
        <meta name="viewport" content="width=device-width, initial-scale=1.0">
        <meta http-equiv="X-UA-Compatible" content="ie=edge">
        <title>Document</title>
    </head>

    <body>

        <h1>hello world</h1>


    <script type="module" src='module.js'></script>


    </body>
    </html>

当我尝试在控制台中初始化Stack的实例时,会得到以下错误。关于给定的错误有很多问题,但我看不出有什么可以帮助我:

    const stack=new Stack()

    Uncaught ReferenceError: Stack is not defined
    at <anonymous>:1:13