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

// reincorporate monitoredItemId and itemToMonitor into the requestedParameters
    requestedParameters.monitoredItemId = monitoredItemId;
    requestedParameters.itemToMonitor = itemToMonitor;


    const monitoredItem = new MonitoredItem(requestedParameters);
    monitoredItem.timestampsToReturn = timestampsToReturn;
    monitoredItem.$subscription = subscription;

    assert(monitoredItem.monitoredItemId === monitoredItemId);
    subscription.monitoredItems[monitoredItemId] = monitoredItem;

    const filterResult = _process_filter(node, requestedParameters.filter);


    const monitoredItemCreateResult = new subscription_service.MonitoredItemCreateResult({
        statusCode: StatusCodes.Good,
        monitoredItemId: monitoredItemId,
        revisedSamplingInterval: monitoredItem.samplingInterval,
        revisedQueueSize: monitoredItem.queueSize,
        filterResult: filterResult
    });
    return monitoredItemCreateResult;
};

function handle_error(statusCode) {
        return new subscription_service.MonitoredItemCreateResult({statusCode: statusCode});
    }