def METHOD_NAME(self):
    template_path = os.path.join(TEST_DATA_DIR, "nested_stack.yaml")
    plugin = CfnIacImplementation(self.sam_cli_context)
    stack = plugin._build_stack(template_path, False, "test_stack")
    nested_stack = stack.sections.get("Resources").section_items[0].nested_stack
    nested_stack_resource_type = nested_stack.sections.get("Resources").section_items[0].body.get("Type")
    self.assertIsInstance(stack, Stack)
    self.assertFalse(stack.is_nested)
    self.assertEqual(stack.stack_id, "test_stack")
    self.assertEqual(stack.name, "test_stack")
    self.assertIsInstance(nested_stack, Stack)
    self.assertTrue(nested_stack.is_nested)
    self.assertEqual(nested_stack.name, "SubApp")
    self.assertEqual(nested_stack_resource_type, "AWS::Serverless::Function")