Events API polyfilled badly?

Hey there,

I am using Snowpack to deal with dependencies. I am aware that Snowpack uses `rollup-plugin-node-polyfills` to polyfill Node built-in modules. I'd like to use a package called `async-mqtt` which relies on node built-in modules (events, stream, buffer). So I installed it with Snowpack, and polyfilled it with this plugin. However, I noticed that the polyfilling process did something strange. I got an error: `Class extends value [object Object] is not a constructor or null`

Now, this error applies for the following code: `class Parser extends events`. So I checked what is the value of `events`, and it turns out, that `events` is an object instead of a class:

```
var events = /*#__PURE__*/Object.freeze({
__proto__: null,
'default': EventEmitter,
EventEmitter: EventEmitter
});
```

Obviously, you cannot extend a class from an object like this. How can I resolve this issue?
Thanks.

Comienza reproduciendo la compilación de Snowpack con async-mqtt y el tratamiento del módulo events por parte de rollup-plugin-node-polyfills. Inspecciona el binding events generado y compáralo con el uso `class Parser extends events` del paquete. Se considera terminado cuando el valor events polyfillado pueda extenderse sin el error de constructor informado.

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