old_contents: from django.conf.urls import url
  from . import views
  
  urlpatterns = [
      url(r'^fridge$', views.Fridge.as_view()),
  ]
  
new_contents: from django.conf.urls import url
  from . import views
  
  urlpatterns = [
      url(r'^fridge$', views.Fridge.as_view()),
      url(r'^door$', views.Door.as_view()),
  ]
  
subject: Add routes