def get_next_id(self):
        try:
            query = {'_id': 'last_id'}
            update = {'$inc': {'id': 1}}
            fn = self.db.internal.find_and_modify
            row = fn(query, update, upsert=True, new=True)
        except Exception as e:
            raise DatabaseException(e)
        return row['id']
def test_reverse_iso8601_datetime():
    dates = [
        ("2011-01-01T00:00:00+00:00", datetime(2011, 1, 1, tzinfo=pytz.utc)),
        ("2011-01-01T23:59:59+00:00", datetime(2011, 1, 1, 23, 59, 59, tzinfo=pytz.utc)),
        ("2011-01-01T23:59:59.001000+00:00", datetime(2011, 1, 1, 23, 59, 59, 1000, tzinfo=pytz.utc)),
        ("2011-01-01T23:59:59+02:00", datetime(2011, 1, 1, 21, 59, 59, tzinfo=pytz.utc))
    ]

    for date_string, expected in dates:
        yield assert_equal, inputs.datetime_from_iso8601(date_string), expected