Various tests cleanup: check_warnings/check_py3k_warnings, unittest.assert* and setUp/tearDown.
diff --git a/Lib/test/test_minidom.py b/Lib/test/test_minidom.py
index f160d09..1f0b229 100644
--- a/Lib/test/test_minidom.py
+++ b/Lib/test/test_minidom.py
@@ -950,7 +950,7 @@
         node = doc.documentElement
         node.childNodes[1].nodeValue = ""
         node.normalize()
-        self.confirm(node.childNodes[-1].nextSibling == None,
+        self.confirm(node.childNodes[-1].nextSibling is None,
                      "Final child's .nextSibling should be None")
 
     def testSiblings(self):