test: Assignment to a __total__ key in class body

In relation to python#109544 which changed this behavior.

Signed-off-by: Daniel Sperber <[email protected]>

Author: Daraan

Lib/test/test_typing.py

@@ -8478,6 +8478,22 @@ class TD2(TD1):
             b: str
 
         self.assertIs(TD2.__total__, True)
+        
+    def test_total_with_value(self):
+        class TD(TypedDict):
+            __total__ = "some_value"
+
+        self.assertIs(TD.__total__, True)
+
+        class TD2(TypedDict, total=True):
+            __total__ = "some_value"
+            
+        self.assertIs(TD2.__total__, True)
+
+        class TD3(TypedDict, total=False):
+            __total__ = "some value"
+
+        self.assertIs(TD3.__total__, False)
 
     def test_optional_keys(self):
         class Point2Dor3D(Point2D, total=False):