Description: Implement TestCase's assertIs method from Python 2.7 to TestOptions class for compatibility with Python 2.6.
Author: Janos Guljas <janos@resenje.org>
Last-Update: 2012-06-27

--- a/tests/test_project.py
+++ b/tests/test_project.py
@@ -472,6 +472,13 @@
 class TestOptions(unittest.TestCase):
     """Test the methods related to parsing the configuration file."""
 
+    def assertIs(self, expr1, expr2, msg=None):
+        """Just like self.assertTrue(a is b), but with a nicer default message."""
+        if expr1 is not expr2:
+            standardMsg = '%s is not %s' % (safe_repr(expr1),
+                                             safe_repr(expr2))
+            self.fail(self._formatMessage(msg, standardMsg))
+
     def setUp(self):
         self.p = Project(init=False)
 
