old_contents: from django.test import TestCase
  
  # Create your tests here.
  
new_contents: from django.test import TestCase
  from .models import Article
  
  
  class ArticleModelTests(TestCase):
  
      def setUp(self):
          Article.objects.create(title='article1',
                                 content='Hello Django\nThis is a article for django development.')
  
      def test_article_summary(self):
          article = Article.objects.get(title='article1')
          self.assertEqual(article.summary(), 'Hello Django')
  
subject: Add test