human
I wrote the below code

    def _OnRecord(verify_response, op):
        callback({'subscription': Subscription.CreateFromITunes(user_id, verify_response).MakeMetadataDict()})
    def _OnVerify(environment, verify_response):
        if ((environment == 'prod') and (verify_response.GetStatus() == VerifyResponse.SANDBOX_ON_PROD_ERROR)):
            ITunesStoreClient.Instance('dev').VerifyReceipt(receipt_data, partial(_OnVerify, 'dev'))
            return
        if (not verify_response.IsValid()):
            logging.warning('record_subscription:    invalid    signature.
   request:    %r', request)
            raise web.HTTPError(400, 'invalid    receipt    signature')
        if (environment == 'prod'):
            op_request = {'headers': request['headers'], 'user_id': user_id, 'verify_response_str': verify_response.ToString()}
            Operation.CreateAndExecute(client, user_id, device_id, 'Subscription.RecordITunesTransactionOperation', op_request, partial(_OnRecord, verify_response))
        else:
            callback({'subscription': Subscription.CreateFromITunes(user_id, verify_response).MakeMetadataDict()})
    receipt_data = base64.b64decode(request['receipt_data'])
    ITunesStoreClient.Instance('prod').VerifyReceipt(receipt_data, partial(_OnVerify, 'prod'))

What's a good function header?
assistant
#Here's a good function header.

def RecordSubscription(client, obj_store, user_id, device_id, request, callback):