<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 async def censusranks(self, scale):
 """Iterate through nations ranked on the World Census scale. If the ranks change while you interate over them, they may be inconsistent. Parameters scale : int A World Census scale, an integer between 0 and 85 inclusive. Returns ------- asynchronous iterator of :class:`CensusRank` """

        order = count(1)
        for offset in count(1, 20):
            census_ranks = await self._get_censusranks(
                scale=scale, start=offset)
            for census_rank in census_ranks:
                assert census_rank.rank == next(order)
                yield census_rank
            if len(census_ranks) < 20:
                break