old_contents: #!/usr/bin/env python3
  import unittest
  
  class CollectionTests(unittest.TestCase):
      """Test of string methods"""
  
      def test_lists(self):
          value = ["hello", "world"]
          self.assertEqual(len(value), 2)
  
      def test_append(self):
          anotherFruit = "peaches"
          container = ["grapes", "apples", "pears"]
          self.assertNotIn(anotherFruit, container)
          container.append(anotherFruit)
          self.assertIn(anotherFruit, container)
  
      def test_extend(self):
          container = [1, 3, 5]
          self.assertNotIn(7, container)
          self.assertNotIn(9, container)
          container += [7, 9]
          self.assertIn(7, container)
          self.assertIn(9, container)
          self.assertNotIn(11, container)
          self.assertNotIn(13, container)
          container.extend([11, 13])
          self.assertIn(11, container)
          self.assertIn(13, container)
  
  
  if __name__ == '__main__':
      unittest.main()
new_contents: #!/usr/bin/env python3
  import unittest
  
  class CollectionTests(unittest.TestCase):
      """Test of string methods"""
  
      def test_lists(self):
          value = ["hello", "world"]
          self.assertEqual(len(value), 2)
  
      def test_append(self):
          anotherFruit = "peaches"
          container = ["grapes", "apples", "pears"]
          self.assertNotIn(anotherFruit, container)
          container.append(anotherFruit)
          self.assertIn(anotherFruit, container)
  
      def test_extend(self):
          container = [1, 3, 5]
          self.assertNotIn(7, container)
          self.assertNotIn(9, container)
          container += [7, 9]
          self.assertIn(7, container)
          self.assertIn(9, container)
          self.assertNotIn(11, container)
          self.assertNotIn(13, container)
          container.extend([11, 13])
          self.assertIn(11, container)
          self.assertIn(13, container)
  
      def test_remove(self):
          container = [1, 3, 6, 5, 7, 9, 11]
          self.assertTrue(6 in container)
          container.remove(6)
          self.assertNotIn(6, container)
          self.assertTrue(3 in container)
          value = container.pop(1)
          self.assertEqual(value, 3)
          self.assertNotIn(3, container)
  
  if __name__ == '__main__':
      unittest.main()
subject: add unit test for methods of list that remove things