Problem with spies

I'm trying to spy on `removeChild` in a test - I have a `parent` node being modified like this:

```
let removals = 0;

let removeChild = parent.removeChild.bind(parent);

parent.removeChild = (child) => {
removals += 1;
return removeChild(child);
};
```

To my surprise, it was counting way too many calls to `removeChild`.

It turns out, several of these methods are being called internally, for brevity.

The real DOM does not call it's own public methods, afaik? If it needs to remove children for other reasons than calls to `removeChild`, it does not internally call the method, it just removed them.

How would you feel about moving the internally reused methods to private methods?

Commencez par l’implémentation de parent.removeChild et suivez les autres méthodes DOM qui l’appellent en interne. Identifiez les opérations réutilisées en interne qui devraient contourner les méthodes publiques, puis vérifiez que les appels explicites à removeChild restent observables, tandis que les suppressions internes n’augmentent plus le compteur.

Rédigé par le modèle d'indexation à partir du texte de l'issue.