How to use the node-opcua-service-subscription.CreateSubscriptionResponse function in node-opcua-service-subscription

self.performMessageTransaction(request, function (err, response) {

        /* istanbul ignore next */
        if (err) {
            return callback(err, response);
        }
        assert(response instanceof subscription_service.CreateSubscriptionResponse);
        callback(null, response);
    });
};

g_session.createSubscription(request, function (err, response) {
            if (!err) {
                response.should.be.instanceof(subscription_service.CreateSubscriptionResponse);
                subscriptionId = response.subscriptionId;
            }
            done(err);

        });
    });

const CloseSessionRequest = session_service.CloseSessionRequest;
const CloseSessionResponse = session_service.CloseSessionResponse;

const DeleteMonitoredItemsRequest = subscription_service.DeleteMonitoredItemsRequest;
const DeleteMonitoredItemsResponse = subscription_service.DeleteMonitoredItemsResponse;

const RepublishRequest = subscription_service.RepublishRequest;
const RepublishResponse = subscription_service.RepublishResponse;

const PublishRequest = subscription_service.PublishRequest;
const PublishResponse = subscription_service.PublishResponse;

const CreateSubscriptionRequest = subscription_service.CreateSubscriptionRequest;
const CreateSubscriptionResponse = subscription_service.CreateSubscriptionResponse;

const DeleteSubscriptionsRequest = subscription_service.DeleteSubscriptionsRequest;
const DeleteSubscriptionsResponse = subscription_service.DeleteSubscriptionsResponse;

const TransferSubscriptionsRequest = subscription_service.TransferSubscriptionsRequest;
const TransferSubscriptionsResponse = subscription_service.TransferSubscriptionsResponse;

const CreateMonitoredItemsRequest = subscription_service.CreateMonitoredItemsRequest;
const CreateMonitoredItemsResponse = subscription_service.CreateMonitoredItemsResponse;

const ModifyMonitoredItemsRequest = subscription_service.ModifyMonitoredItemsRequest;
const ModifyMonitoredItemsResponse = subscription_service.ModifyMonitoredItemsResponse;
const MonitoredItemModifyResult = subscription_service.MonitoredItemModifyResult;

const MonitoredItemCreateResult = subscription_service.MonitoredItemCreateResult;
const SetPublishingModeRequest = subscription_service.SetPublishingModeRequest;