text: from django.db import models
  
  
  class ItemQuerySet(models.QuerySet):
      def active(self):
          return self.filter(active=True)
  
      def visible(self):
          return self.filter(visible=True)
  
  
  class ItemManager(models.Manager):
      queryset_class = ItemQuerySet
  
      def get_queryset(self):
          return self.queryset_class(self.model, using=self._db)
  
      def active(self):
          return self.get_queryset().active()
  
      def visible(self):
          return self.get_queryset().visible()
  