old_contents: from django.test import TestCase
  
  from eca_catalogue.tests.models import NestedProductCategory
  from eca_catalogue.tests.factories import ProductCategoryFactory, ProductFactory, SellingPointFactory
  
  
  class ProductCategoryTestCase(TestCase):
      def test_model(self):
          obj = ProductCategoryFactory()
          self.assertTrue(obj.pk)
  
  
  class NestedProductCategoryTestCase(TestCase):
      def test_model(self):
          obj = NestedProductCategory.add_root(name="cat1", slug="cat1")
          self.assertTrue(obj.pk)
  
  
  class ProductTestCase(TestCase):
      def test_model(self):
          obj = ProductFactory()
          self.assertTrue(obj.pk)
  
  
  class SellingPointTest(TestCase):
      def test_model(self):
          obj = SellingPointFactory()
          self.assertTrue(obj.pk)
  
new_contents: from django.test import TestCase
  
  from eca_catalogue.tests.models import NestedProductCategory
  from eca_catalogue.tests.factories import ProductCategoryFactory, ProductFactory, SellingPointFactory
  
  
  class ProductCategoryTestCase(TestCase):
      def test_model(self):
          obj = ProductCategoryFactory()
          self.assertTrue(obj.pk)
  
  
  class NestedProductCategoryTestCase(TestCase):
      def test_model(self):
          obj = NestedProductCategory.add_root(name="cat1", slug="cat1")
          self.assertTrue(obj.pk)
  
  
  class ProductTestCase(TestCase):
      def test_model(self):
          obj = ProductFactory()
          self.assertTrue(obj.pk)
  
  
  class SellingPointTest(TestCase):
      def test_model(self):
          obj = SellingPointFactory()
          self.assertTrue(obj.pk)
  
  
subject: add missing newline