text: from collections import MutableMapping
  
  from django.contrib.sitemaps.views import sitemap
  from django.http import HttpResponse
  from django.urls import include, path
  
  from docs.models import DocumentRelease
  from docs.sitemaps import DocsSitemap
  from docs.urls import urlpatterns as docs_urlpatterns
  from docs.views import sitemap_index
  
  
  class Sitemaps(MutableMapping):
      """Lazy dict to allow for later additions to DocumentRelease languages."""
      _data = {}
  
      def __iter__(self):
          return iter(
              DocumentRelease.objects.values_list('lang', flat=True).distinct().order_by('lang')
          )
  
      def __getitem__(self, key):
          if key not in self._data:
              if not DocumentRelease.objects.filter(lang=key).exists():
                  raise KeyError
              self._data[key] = DocsSitemap(key)
          return self._data[key]
  
      def __len__(self):
          return len(self.keys())
  
      def __delitem__(key):
          raise NotImplementedError
  
      def __setitem__(key, value):
          raise NotImplementedError
  
  
  sitemaps = Sitemaps()
  
  urlpatterns = docs_urlpatterns + [
      path('sitemap.xml', sitemap_index, {'sitemaps': sitemaps}),
      path('sitemap-<section>.xml', sitemap, {'sitemaps': sitemaps}, name='document-sitemap'),
      path('google79eabba6bf6fd6d3.html', lambda req: HttpResponse('google-site-verification: google79eabba6bf6fd6d3.html')),
      # This just exists to make sure we can proof that the error pages work under both hostnames.
      path('', include('legacy.urls')),
  ]
  