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?

Start at the implementation of parent.removeChild and trace the other DOM methods that invoke it internally. Identify the internally reused operations that should bypass public methods, then verify that explicit removeChild calls remain observable while internal removals no longer inflate the count.

Written by the indexing model from the issue text.