old_contents: from django.test.testcases import TestCase as DjangoTestCase
  from django.forms import ModelForm
  from tests.someapp.models import Book
  
  
  class BookForm(ModelForm):
      class Meta:
          model = Book
          fields = ['title']
  
  
  class ModelFormTest(DjangoTestCase):
  
      def test_define(self):
          self.assertTrue(issubclass(BookForm, ModelForm))
  
      def test_can_validate(self):
          bf = BookForm(data={'title': 'Harry Potter 3'})
          self.assertTrue(bf.is_valid())
  
      def test_can_save(self):
          bf = BookForm(data={'title': 'Harry Potter 2'})
          bf.save(True)
  
      def test_unique_is_checked(self):
          BookForm(data={'title': 'book1'}).save()
          self.assertFalse(BookForm(data={'title': 'book1'}).is_valid())
  
      def test_can_update(self):
          hp = Book(title='Harrry').save()
          bf = BookForm(data={'title': 'Harry Potter'}, instance=hp)
          bf.save(True)
new_contents: from django.test.testcases import TestCase as DjangoTestCase
  from django.forms import ModelForm
  from tests.someapp.models import Book
  
  
  class BookForm(ModelForm):
      class Meta:
          model = Book
          fields = ['title']
  
  
  class ModelFormTest(DjangoTestCase):
  
      def test_define(self):
          self.assertTrue(issubclass(BookForm, ModelForm))
  
      def test_can_validate(self):
          bf = BookForm(data={'title': 'Harry Potter 3'})
          self.assertTrue(bf.is_valid())
  
      def test_can_save(self):
          bf = BookForm(data={'title': 'Harry Potter 2'})
          bf.save(True)
  
      def test_unique_is_checked(self):
          BookForm(data={'title': 'book1'}).save()
          self.assertFalse(BookForm(data={'title': 'book1'}).is_valid())
  
      def test_can_update(self):
          hp = Book(title='Harrry').save()
          bf = BookForm(data={'title': 'Harry Potter'}, instance=hp)
          bf.save(True)
  
      def test_can_render(self):
          bf = BookForm(data={'title': 'Harry Potter'})
          self.assertIn('Harry Potter', bf.__html__())
subject: Add test for rendering