old_contents: """
  Page navigation groups allow assigning pages to differing navigation lists
  such as header, footer and what else.
  """
  
  from __future__ import absolute_import, unicode_literals
  
  from django.db import models
  from django.utils.translation import ugettext_lazy as _
  
  from feincms import extensions
  
  
  class Extension(extensions.Extension):
      ident = 'navigationgroups'
      groups = [
          ('default', _('Default')),
          ('footer', _('Footer')),
      ]
  
      def handle_model(self):
          self.model.add_to_class(
              'navigation_group',
              models.CharField(
                  _('navigation group'),
                  choices=self.groups,
                  default=self.groups[0][0],
                  max_length=20,
                  db_index=True))
  
      def handle_modeladmin(self, modeladmin):
          modeladmin.add_extension_options(['navigation_group'])
          modeladmin.extend_list('list_display', ['navigation_group'])
          modeladmin.extend_list('list_filter', ['navigation_group'])
  
new_contents: """
  Page navigation groups allow assigning pages to differing navigation lists
  such as header, footer and what else.
  """
  
  from __future__ import absolute_import, unicode_literals
  
  from django.db import models
  from django.utils.translation import ugettext_lazy as _
  
  from feincms import extensions
  
  
  class Extension(extensions.Extension):
      ident = 'navigationgroups'
      groups = [
          ('default', _('Default')),
          ('footer', _('Footer')),
      ]
  
      def handle_model(self):
          self.model.add_to_class(
              'navigation_group',
              models.CharField(
                  _('navigation group'),
                  choices=self.groups,
                  default=self.groups[0][0],
                  max_length=20,
                  db_index=True))
  
      def handle_modeladmin(self, modeladmin):
          modeladmin.add_extension_options('navigation_group')
          modeladmin.extend_list('list_display', ['navigation_group'])
          modeladmin.extend_list('list_filter', ['navigation_group'])
  
subject: Fix a typo