ERP5TypeTestCase: backport python3 assertion method names

so that we can run 2to3.fix_assert

product/ERP5Type/tests/ERP5TypeTestCase.py

@@ -679,6 +679,15 @@ class ERP5TypeTestCaseMixin(ProcessingNodeTestCase, PortalTestCase):
       self.assertEqual(method(), reference_workflow_state)
       return workflow_error_message
 
+    # BBB backport methods from python3.
+    # We use this tricky getattr syntax so that lib2to3.fixers.fix_asserts
+    # do not fix this code.
+    if six.PY2:
+      def assertRaisesRegex(self, *args, **kwargs):
+        return getattr(self, 'assertRaisesRegexp')(*args, **kwargs)
+      def assertRegex(self, *args, **kwargs):
+        return getattr(self, 'assertRegexpMatches')(*args, **kwargs)
+
     def stepPdb(self, sequence=None, sequence_list=None):
       """Invoke debugger"""
       try: # try ipython if available