I see what you're doing with self.data in this file, but I'm not wildly excited about setting up a test by taking some thing and removing the things you don't want in it. If we ever add to that thing, we have to go find all the places we remove things and remove the new stuff, too.

I think it's better to explicitly define it here with:

```
data = {'product': self.data['product']}
```

Or something like that.