old_contents: from django.test import TestCase
  
  # Create your tests here.
  
new_contents: from django.test import TestCase, Client
  
  class BillingTestCase(TestCase):
      ''' Test billing creation and modification '''
  
      def setUp(self):
          self.client = Client()
          self.client.login(username='bill', password='jobs')
  
      def tearDown(self):
          self.client.logout()
  
      def test_create_bill_with_one_line(self):
          ''' Test when user is created a bill with a single service '''
          response = self.client.get('/admin/billjobs/bill/add/', follow_redirect=True)
          self.assertEqual(response.status_code, 200)
  
  
subject: Create functional tests