Patch# 1258 by Christian Heimes: kill basestring.
I like this because it makes the code shorter! :-)
diff --git a/Lib/test/test_support.py b/Lib/test/test_support.py
index 5b2176e..fb634f6 100644
--- a/Lib/test/test_support.py
+++ b/Lib/test/test_support.py
@@ -529,7 +529,7 @@
     valid_types = (unittest.TestSuite, unittest.TestCase)
     suite = unittest.TestSuite()
     for cls in classes:
-        if isinstance(cls, basestring):
+        if isinstance(cls, str):
             if cls in sys.modules:
                 suite.addTest(unittest.findTestCases(sys.modules[cls]))
             else: