<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 submit_batches(self, request):
 """Accepts a binary encoded BatchList and submits it to the validator. Request: body: octet-stream BatchList of one or more Batches Response: status: - 202: Batches submitted and pending link: /batches or /batch_statuses link for submitted batches """

        timer_ctx = self._post_batches_total_time.time()
        self._post_batches_count.inc()

        # Parse request
        if request.headers['Content-Type'] != 'application/octet-stream':
            LOGGER.debug(
                'Submission headers had wrong Content-Type: %s',
                request.headers['Content-Type'])
            self._post_batches_error.inc()
            raise errors.SubmissionWrongContentType()

        body = await request.read()
        if not body:
            LOGGER.debug('Submission contained an empty body')
            self._post_batches_error.inc()
            raise errors.NoBatchesSubmitted()

        try:
            batch_list = BatchList()
            batch_list.ParseFromString(body)
        except DecodeError:
            LOGGER.debug('Submission body could not be decoded: %s', body)
            self._post_batches_error.inc()
            raise errors.BadProtobufSubmitted()

        # Query validator
        error_traps = [error_handlers.BatchInvalidTrap,
                       error_handlers.BatchQueueFullTrap]
        validator_query = client_batch_submit_pb2.ClientBatchSubmitRequest(
            batches=batch_list.batches)

        with self._post_batches_validator_time.time():
            await self._query_validator(
                Message.CLIENT_BATCH_SUBMIT_REQUEST,
                client_batch_submit_pb2.ClientBatchSubmitResponse,
                validator_query,
                error_traps)

        # Build response envelope
        id_string = ','.join(b.header_signature for b in batch_list.batches)

        status = 202
        link = self._build_url(request, path='/batch_statuses', id=id_string)

        retval = self._wrap_response(
            request,
            metadata={'link': link},
            status=status)

        timer_ctx.stop()
        return retval