add a test for an assertion with tuple msg

Lib/test/test_raise.py

@@ -130,6 +130,13 @@ class TestRaise(unittest.TestCase):
         with self.assertRaises(TypeError):
             raise MyException
 
+    def test_assert_with_tuple_arg(self):
+        try:
+            assert False, (3,)
+        except AssertionError as e:
+            self.assertEqual(str(e), "(3,)")
+
+
 
 class TestCause(unittest.TestCase):
     def test_invalid_cause(self):