convert old fail* assertions to assert*
diff --git a/Lib/test/test_base64.py b/Lib/test/test_base64.py
index 149ac8a..fadee6d 100644
--- a/Lib/test/test_base64.py
+++ b/Lib/test/test_base64.py
@@ -204,7 +204,7 @@
         self.assertRaises(TypeError, base64.b16decode, "")
 
     def test_ErrorHeritage(self):
-        self.assert_(issubclass(binascii.Error, ValueError))
+        self.assertTrue(issubclass(binascii.Error, ValueError))