new_contents: import django_filters
  from django.utils.translation import gettext_lazy as _
  
  from adhocracy4.filters.widgets import DropdownLinkWidget
  
  from . import models
  
  
  class LabelFilterWidget(DropdownLinkWidget):
      label = _('Label')
  
  
  class LabelFilter(django_filters.ModelChoiceFilter):
  
      def __init__(self, *args, **kwargs):
          if 'queryset' not in kwargs:
              kwargs['queryset'] = None
          if 'widget' not in kwargs:
              kwargs['widget'] = LabelFilterWidget
          super().__init__(*args, **kwargs)
  
      def get_queryset(self, request):
          if self.queryset is None:
              return models.Label.objects.filter(
                  module=self.view.module
              )
          else:
              return super().get_queryset(request)
  
subject: add label filter