Gets the Data Center (DC) associated to 'dc_id

async def _get_dc(self, dc_id, cdn=False):
        """Gets the Data Center (DC) associated to 'dc_id'"""
        cls = self.__class__
        if not cls._config:
            cls._config = await self(functions.help.GetConfigRequest())

        if cdn and not self._cdn_config:
            cls._cdn_config = await self(functions.help.GetCdnConfigRequest())
            for pk in cls._cdn_config.public_keys:
                rsa.add_key(pk.public_key)

        return next(
            dc for dc in cls._config.dc_options
            if dc.id == dc_id
            and bool(dc.ipv6) == self._use_ipv6 and bool(dc.cdn) == cdn
        )