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 import sys

 info = sys.version_info

 if info[:3] >= (3, 2, 0):

     # for Python 3.2 ordinary unittest is fine

     import unittest as unittest2

 else:

     import unittest2

 try:

     callable = callable

 except NameError:

     def callable(obj):

         return hasattr(obj, '__call__')

 inPy3k = sys.version_info[0] == 3

 with_available = sys.version_info[:2] >= (2, 5)

 def is_instance(obj, klass):

     """Version of is_instance that doesn't access __class__"""

     return issubclass(type(obj), klass)

 class SomeClass(object):

     class_attribute = None

     def wibble(self):

         pass

 class X(object):

     pass

 try:

     next = next

 except NameError:

     def next(obj):

         return obj.next()