#! /usr/bin/env python

class subitem:
	def __init__(self, parent):
		self.parent = parent
		if parent != None:
			parent.append(self)

class group(subitem, list):
	def __init__(self, parent):
		subitem.__init__(self, parent)
		

g = group(None)
s = subitem(g)

import cPickle
print cPickle.dumps(g)

import pickle
print pickle.dumps(g)