Disclaimer: I'm not a coffeescript person so I could be completely wrong.

It looks like you're reaching into the compiled javascript to get that instance variable with `@page['_statusCode']`, which gets translated to `this.page['_statusCode']` in javascript; this works, but is fragile because you're both reaching into an object's private api and depending on technicalities in the coffeescript->javascript translation.

It can be avoided in pure coffeescript by using the `@page.statusCode` [method](https://github.com/dholdren/poltergeist/blob/3c923535bfc987585dab8334cbca85876a33906f/lib/capybara/poltergeist/client/web_page.coffee#L121-L122), which exposes that instance variable for public reading.