text: from datetime import datetime
  
  from django.db import models
  from django.db.models.query import QuerySet
  
  
  class NewsQuerySet(QuerySet):
  
      def published(self):
          return self.filter(publish_date__lte=datetime.now()).order_by('-publish_date')
  
  
  class NewsManager(models.Manager):
  
      def get_queryset(self):
          return NewsQuerySet(self.model, using=self._db)
  
      def published(self):
          return self.get_queryset().published()