old_contents: import webapp2
  
  from . import app
  
  routes = [
    webapp2.Route("/", app.Index),
    webapp2.Route("/index.html", app.ForMobile),
  ]
  
new_contents: import webapp2
  
  from . import app
  
  prefixed = lambda s: "{0}.app.{1}".format(__package__, s)
  
  routes = [
    webapp2.Route("/", prefixed("Index")),
    webapp2.Route("/index.html", app.ForMobile),
  ]
  
subject: update sample app