subclass urllib2

[monkeys paw]

I'm trying to subclass urllib2 in order to mask the
version attribute. Here's what i'm using:

import urllib2

class myURL(urllib2):
     def __init__(self):
         urllib2.__init__(self)
         self.version = 'firefox'

I get this>
Traceback (most recent call last):
   File "<interactive input>", line 1, in <module>
TypeError: Error when calling the metaclass bases
module.__init__() takes at most 2 arguments (3 given)

I don't see where i am supplying 3 arguments. What am i
missing?