Currently page is used to register all routes. This is problematic for scenarios with multiple tabs or popups. I think it would make sense to use context as the default: it is limited to a specific test just like page but works on all pages within the test. An additional option would be to allow both page and context to be passed to NetworkFixture by allowing more broad types.

The only problem currently is that the NetworkFixture uses page.url() which is not available in context.