How about we ship routes.examples.py with this code in it?
routes_onerror = [
('*/400','http://httpcats.herokuapp.com/401'),
('*/401','http://httpcats.herokuapp.com/401'),
('*/403','http://httpcats.herokuapp.com/403'),
('*/404','http://httpcats.herokuapp.com/404'),
('*/405','http://httpcats.herokuapp.com/405'),
('*/406','http://httpcats.herokuapp.com/406'),
('*/407','http://httpcats.herokuapp.com/407'),
('*/408','http://httpcats.herokuapp.com/408'),
('*/501','http://httpcats.herokuapp.com/501'),
]
