old_contents: # -*- encoding: utf-8 -*-
  """
  
  """
  
  import unittest
  import time
  
  class Case1(unittest.TestCase):
  
      def test_success(self):
          time.sleep(0.5)
          self.assertEqual(1, 1)
  
      def test_failure(self):
          time.sleep(0.5)
          self.assertEqual(1, 2)
  
      @unittest.skip("because")
      def test_skip(self):
          time.sleep(0.1)
          self.assertFalse(True)
  
      @unittest.expectedFailure
      def test_expected_failure(self):
          time.sleep(0.1)
          self.assertEqual(1, 0, "broken")
  
      @unittest.expectedFailure
      def test_unexpected_success(self):
          time.sleep(0.1)
          self.assertEqual(1, 1, "not broken after all")
  
  class Case2(unittest.TestCase):
  
      def test_success(self):
          self.assertTrue(True)
  
  class EmptyCase(unittest.TestCase):
      pass
  
new_contents: # -*- encoding: utf-8 -*-
  """
  
  """
  
  import unittest
  import time
  
  class Case1(unittest.TestCase):
  
      def test_success(self):
          time.sleep(0.5)
          self.assertEqual(1, 1)
  
      def test_failure(self):
          time.sleep(0.5)
          self.assertEqual(1, 2)
  
      @unittest.skip("because")
      def test_skip(self):
          time.sleep(0.1)
          self.assertFalse(True)
  
      @unittest.expectedFailure
      def test_expected_failure(self):
          time.sleep(0.1)
          self.assertEqual(1, 0, "broken")
  
      @unittest.expectedFailure
      def test_unexpected_success(self):
          time.sleep(0.1)
          self.assertEqual(1, 1, "not broken after all")
  
      def test_error(self):
          raise RuntimeError("error raised for testing purpose")
  
  class Case2(unittest.TestCase):
  
      def test_success(self):
          self.assertTrue(True)
  
  class EmptyCase(unittest.TestCase):
      pass
  
subject: Add a sample of erroneous test.