Address review

Author: sobolevn

Lib/test/test_popen.py

@@ -58,16 +58,20 @@ def test_contextmanager(self):
         with os.popen("echo hello") as f:
             self.assertEqual(f.read(), "hello\n")
             self.assertFalse(f.closed)
+        self.assertTrue(f.closed)
 
     def test_iterating(self):
         with os.popen("echo hello") as f:
             self.assertEqual(list(f), ["hello\n"])
             self.assertFalse(f.closed)
+        self.assertTrue(f.closed)
 
     def test_keywords(self):
         with os.popen(cmd="echo hello", mode="r", buffering=-1) as f:
             self.assertEqual(f.read(), "hello\n")
             self.assertFalse(f.closed)
+        self.assertTrue(f.closed)
+
 
 if __name__ == "__main__":
     unittest.main()