broken instanceof check with Document Fragment

[coffeeandwork]

Describe the bug
If you create a document fragment object using document.createDocumentFragment() and then you check whether the returned value is an instance of DocumentFragment using happy-dom, we get a return value of false.

To Reproduce
Steps to reproduce the behavior:

1. Create a DocumentFragment object

const myElement = document.createDocumentFragment();

3. Run the instanceof check

console.log('is my element a DocumentFragment?:', myElement instanceof DocumentFragment);

3. Observe that the output of above shows:

is my element a DocumentFragment?: false

The full code using happy-dom:

import { GlobalRegistrator } from '@happy-dom/global-registrator';

GlobalRegistrator.register();

const myElement = document.createDocumentFragment();
console.log('is my element a DocumentFragment?:', myElement instanceof DocumentFragment);

await GlobalRegistrator.unregister();