There was a parenthesis in the guides, which resulted in the one link not working, and a second link not even showing.

Of course, in a production environment you would need much more robust code, and could use a plugin such as Iain Hecker's [http_accept_language](https://github.com/iain/http_accept_language/tree/master or even Rack middleware such as Ryan Tomayko's [locale](https://github.com/rack/rack-contrib/blob/master/lib/rack/contrib/locale.rb).

Should be:

Of course, in a production environment you would need much more robust code, and could use a plugin such as Iain Hecker's [http_accept_language](https://github.com/iain/http_accept_language/tree/master) or even Rack middleware such as Ryan Tomayko's [locale](https://github.com/rack/rack-contrib/blob/master/lib/rack/contrib/locale.rb).