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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:
 async def _process_polling_updates(self, updates, fast: typing.Optional[bool] = True):
 """ Process updates received from long-polling. :param updates: list of updates. :param fast: """

        need_to_call = []
        for responses in itertools.chain.from_iterable(await self.process_updates(updates, fast)):
            for response in responses:
                if not isinstance(response, BaseResponse):
                    continue
                need_to_call.append(response.execute_response(self.bot))
        if need_to_call:
            try:
                asyncio.gather(*need_to_call)
            except TelegramAPIError:
                log.exception('Cause exception while processing updates.')