[3.9] bpo-46482: add a test for typing.Annotation.__new__ (GH-30821) (GH-31045)

(cherry picked from commit 4c0612a)


Co-authored-by: Nikita Sobolev <[email protected]>

Automerge-Triggered-By: GH:Fidget-Spinner

Author: miss-islington

Lib/test/test_typing.py

@@ -4158,6 +4158,13 @@ class A(typing.Match):
 
 class AnnotatedTests(BaseTestCase):
 
+    def test_new(self):
+        with self.assertRaisesRegex(
+            TypeError,
+            'Type Annotated cannot be instantiated',
+        ):
+            Annotated()
+
     def test_repr(self):
         self.assertEqual(
             repr(Annotated[int, 4, 5]),