Creates a new exported `MTProtoSender` for the given `dc_id` and
        returns it. This method should be used by `_borrow_exported_sender`.

async def _create_exported_sender(self, dc_id):
        """
        Creates a new exported `MTProtoSender` for the given `dc_id` and
        returns it. This method should be used by `_borrow_exported_sender`.
        """
        # Thanks badoualy/kotlogram on /telegram/api/DefaultTelegramClient.kt
        # for clearly showing how to export the authorization
        dc = await self._get_dc(dc_id)
        # Can't reuse self._sender._connection as it has its own seqno.
        #
        # If one were to do that, Telegram would reset the connection
        # with no further clues.
        sender = MTProtoSender(None, self._loop, loggers=self._log)
        await sender.connect(self._connection(
            dc.ip_address,
            dc.port,
            dc.id,
            loop=self._loop,
            loggers=self._log,
            proxy=self._proxy
        ))
        self._log[__name__].info('Exporting authorization for data center %s',
                                 dc)
        auth = await self(functions.auth.ExportAuthorizationRequest(dc_id))
        req = self._init_with(functions.auth.ImportAuthorizationRequest(
            id=auth.id, bytes=auth.bytes
        ))
        await sender.send(req)
        return sender