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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _mangle_prefix(res):
 """ Mangle prefix result """

    # fugly cast from large numbers to string to deal with XML-RPC
    res['total_addresses'] = unicode(res['total_addresses'])
    res['used_addresses'] = unicode(res['used_addresses'])
    res['free_addresses'] = unicode(res['free_addresses'])

    # postgres has notion of infinite while datetime hasn't, if expires
    # is equal to the max datetime we assume it is infinity and instead
    # represent that as None
    if res['expires'].tzinfo is None:
        res['expires'] = pytz.utc.localize(res['expires'])
    if res['expires'] == pytz.utc.localize(datetime.datetime.max):
        res['expires'] = None

    return res