old_contents: from django.contrib import admin
  from django.utils.translation import ugettext_lazy as _
  from .forms import FlatpageForm
  from .flatpages.models import FlatPage
  
  
  class FlatPageAdmin(admin.ModelAdmin):
      form = FlatpageForm
      fieldsets = (
          (None, {'fields': ('url', 'title', 'content', 'sites')}),
          (_('Advanced options'), {'classes': ('collapse',),
          'fields': ('enable_comments', 'registration_required', 'template_name')}),
      )
      list_display = ('url', 'title')
      list_filter = ('sites', 'enable_comments', 'registration_required')
      search_fields = ('url', 'title')
  
  admin.site.register(FlatPage, FlatPageAdmin)
  
new_contents: from django.contrib import admin
  from django.utils.translation import ugettext_lazy as _
  from .forms import FlatpageForm
  from .models import FlatPage
  
  
  class FlatPageAdmin(admin.ModelAdmin):
      form = FlatpageForm
      fieldsets = (
          (None, {'fields': ('url', 'title', 'content', 'sites')}),
          (_('Advanced options'), {'classes': ('collapse',),
          'fields': ('enable_comments', 'registration_required', 'template_name')}),
      )
      list_display = ('url', 'title')
      list_filter = ('sites', 'enable_comments', 'registration_required')
      search_fields = ('url', 'title')
  
  admin.site.register(FlatPage, FlatPageAdmin)
  
subject: Correct Import