text: from django.db import models
  
  #create our custom queries, which we will be easier to call
  #create the active query to get only the products we want to show and next with have_qty we filter them 
  # to check if we have qty in warehouse
  class ProductManager(models.Manager):
  
      def active(self):
          return self.filter(active=True)
  
      def have_qty(self):
          return self.active().filter(qty__gte=1)