new_contents: from unittest import TestCase
  from classes.item import Item
  
  
  class TestShoppingList(TestCase):
      def setUp(self):
          self.item = Item("name")
  
      def tearDown(self):
          self.item = None
  
      def test_item_id_is_int(self):
          self.assertIsInstance(self.item.id, int)
  
      def test_item_name_is_str(self):
          self.assertIsInstance(self.item.name, str)
  
      def test_update_item_without_name(self):
          self.assertTrue(self.item.update(None), "Item must have a name")
  
      def test_update_item_with_invalid_name(self):
          self.assertTrue(self.item.update([]), "Item name must be a string")
  
      def test_update_item(self):
          self.item.update("new name")
  
          self.assertEqual(
              self.item.name,
              "new name",
              msg="Method update should update the items name"
          )
  
subject: Create test-cases for class item