sligtly change test on _utils and add page2 example

tests/utils_pagination_test.py

@@ -121,19 +121,20 @@ def test_fetch_next_page_no_next_link(self):
     @patch("fhirclient._utils._execute_pagination_request")
     def test_iter_pages(self, mock_fetch_next_page):
         inst = self.instantiate_from("bundle-example.json")
+        inst_page2 = self.instantiate_from("bundle-example-page2.json")
 
         # Set up the mock to return a new bundle, then None to stop iteration
-        mock_fetch_next_page.side_effect = [inst, None]
+        mock_fetch_next_page.side_effect = [inst_page2, None]
         pages = list(iter_pages(inst))
 
         # Check that two bundles were returned (the first bundle and the one from mock)
         self.assertEqual(len(pages), 2)
         self.assertIsInstance(pages[0], Bundle)
         self.assertIsInstance(pages[1], Bundle)
 
-        # Compare JSON representations instead of object instances
+        self.assertNotEqual(pages[0].as_json(), pages[1].as_json())  # Ensure the two pages are different
         self.assertEqual(pages[0].as_json(), inst.as_json())
-        self.assertEqual(pages[1].as_json(), inst.as_json())
+        self.assertEqual(pages[1].as_json(), inst_page2.as_json())  # Ensure the second page is correct
 
         # Ensure that _fetch_next_page was called twice
         self.assertEqual(mock_fetch_next_page.call_count, 2)