--- a/tests/unit.py	Wed Jul 04 09:54:37 2012 -0700
+++ b/tests/unit.py	Mon Oct 01 17:08:45 2012 -0700
@@ -203,5 +203,29 @@
         expected = datetime.datetime(2012, 7, 4, 0, 0)
         self.assertEqual(example.config['datestring'], expected)
 
+
+    def test_added(self):
+        """test that we keep track of things added to the configuration"""
+
+        # make an example class
+        class AddedExample(configuration.Configuration):
+            options = {'foo': {},
+                       'bar': {}}
+
+        # parse it; there should be nothing
+        instance = AddedExample()
+        instance()
+        self.assertEqual(instance.added, set())
+
+        # parse it; there should be one thing
+        instance = AddedExample()
+        instance({'foo': 'foo'})
+        self.assertEqual(instance.added, set(['foo']))
+
+        # parse it; there should be two things
+        instance = AddedExample()
+        instance({'foo': 'foo'}, {'foo': 'FOO', 'bar': 'bar'})
+        self.assertEqual(instance.added, set(['foo', 'bar']))
+
 if __name__ == '__main__':
     unittest.main()