How to use the node-opcua-address-space.UAVariable function in node-opcua-address-space

const _ = require("underscore");

const AttributeIds = require("node-opcua-data-model").AttributeIds;

const SequenceNumberGenerator = require("node-opcua-secure-channel").SequenceNumberGenerator;

const EventEmitter = require("events").EventEmitter;
const util = require("util");

const SessionContext = require("node-opcua-address-space").SessionContext;

const EventFilter = require("node-opcua-service-filter").EventFilter;
const DataChangeFilter = require("node-opcua-service-subscription").DataChangeFilter;
const AggregateFilter = require("node-opcua-service-subscription").AggregateFilter;

const UAVariable = require("node-opcua-address-space").UAVariable;
const validateFilter = require("./validate_filter").validateFilter;
const isValidDataEncoding = require("node-opcua-data-model").isValidDataEncoding;


const debugLog = require("node-opcua-debug").make_debugLog(__filename);
const doDebug = require("node-opcua-debug").checkDebugFlag(__filename);


const SubscriptionState = new Enum([
    "CLOSED",   // The Subscription has not yet been created or has terminated.
    "CREATING", // The Subscription is being created
    "NORMAL",   // The Subscription is cyclically checking for Notifications from its MonitoredItems.
                // The keep-alive counter is not used in this state.
    "LATE",     // The publishing timer has expired and there are Notifications available or a keep-alive Message is
                // ready to be sent, but there are no Publish requests queued. When in this state, the next Publish
                // request is processed when it is received. The keep-alive counter is not used in this state.

module.exports.ServerEngine = require("node-opcua-server").ServerEngine;
module.exports.MonitoredItem = require("node-opcua-server").MonitoredItem;
module.exports.ServerSession = require("node-opcua-server").ServerSession;
module.exports.Subscription = require("node-opcua-server").Subscription;
module.exports.MonitoredItem = require("node-opcua-server").MonitoredItem;

module.exports.generate_address_space = require("node-opcua-address-space").generate_address_space;
module.exports.AddressSpace = require("node-opcua-address-space").AddressSpace;
module.exports.Namespace = require("node-opcua-address-space").Namespace;

module.exports.SessionContext = require("node-opcua-address-space").SessionContext;
// basic opcua NodeClass
module.exports.UAObject = require("node-opcua-address-space").UAObject;
module.exports.UAMethod = require("node-opcua-address-space").UAMethod;
module.exports.UAVariable = require("node-opcua-address-space").UAVariable;
module.exports.UADataType = require("node-opcua-address-space").UADataType;

module.exports.getAddressSpaceFixture = require("node-opcua-address-space/test_helpers/get_address_space_fixture").getAddressSpaceFixture;
module.exports.OPCUADiscoveryServer = require("node-opcua-server-discovery").OPCUADiscoveryServer;

module.exports.basic_types = require("node-opcua-basic-types");

// version
module.exports.version = require("./package.json").version;

module.exports.nodesets = require("node-opcua-nodesets");
module.exports.constructNodesetFilename = module.exports.nodesets.constructNodesetFilename;
module.exports.standard_nodeset_file = module.exports.nodesets.standard_nodeset_file;
module.exports.di_nodeset_filename = module.exports.nodesets.di_nodeset_filename;
module.exports.adi_nodeset_filename = module.exports.nodesets.adi_nodeset_filename;

const AttributeIds = require("node-opcua-data-model").AttributeIds;
const BaseNode = require("node-opcua-address-space").BaseNode;

const sameDataValue = require("node-opcua-data-value").sameDataValue;
const sameVariant = require("node-opcua-variant").sameVariant;
const isValidVariant = require("node-opcua-variant").isValidVariant;

const MonitoringMode = subscription_service.MonitoringMode;
const MonitoringParameters = subscription_service.MonitoringParameters;
const MonitoredItemModifyResult = subscription_service.MonitoredItemModifyResult;
const TimestampsToReturn = read_service.TimestampsToReturn;
const EventFilter = require("node-opcua-service-filter").EventFilter;
const apply_timestamps = require("node-opcua-data-value").apply_timestamps;

const UAVariable = require("node-opcua-address-space").UAVariable;

const defaultItemToMonitor = {indexRange: null, attributeId: read_service.AttributeIds.Value};

const SessionContext = require("node-opcua-address-space").SessionContext;
const NumericRange = require("node-opcua-numeric-range").NumericRange;



const debugLog = require("node-opcua-debug").make_debugLog(__filename);
const doDebug = require("node-opcua-debug").checkDebugFlag(__filename);

function _adjust_sampling_interval(samplingInterval,node_minimumSamplingInterval) {

    assert(_.isNumber(node_minimumSamplingInterval,"expecting a number"));

    if (samplingInterval === 0) {

const resolveNodeId = require("node-opcua-nodeid").resolveNodeId;
const makeNodeId = require("node-opcua-nodeid").makeNodeId;
const NodeIdType = require("node-opcua-nodeid").NodeIdType;
const NumericRange = require("node-opcua-numeric-range").NumericRange;
const BrowseDirection = require("node-opcua-data-model").BrowseDirection;
const BrowseResult = require("node-opcua-service-browse").BrowseResult;

const ReadRequest = require("node-opcua-service-read").ReadRequest;

require("node-opcua-common");

const read_service = require("node-opcua-service-read");
const AttributeIds = require("node-opcua-data-model").AttributeIds;
const TimestampsToReturn = read_service.TimestampsToReturn;

const UAVariable = require("node-opcua-address-space").UAVariable;
const ServerSidePublishEngine = require("./server_publish_engine").ServerSidePublishEngine;

const historizing_service = require("node-opcua-service-history");
const HistoryReadRequest = historizing_service.HistoryReadRequest;
const HistoryReadDetails = historizing_service.HistoryReadDetails;
const HistoryReadResult = historizing_service.HistoryReadResult;

const DataValue = require("node-opcua-data-value").DataValue;
const Variant = require("node-opcua-variant").Variant;
const DataType = require("node-opcua-variant").DataType;
const VariantArrayType = require("node-opcua-variant").VariantArrayType;
const isValidVariant = require("node-opcua-variant").isValidVariant;


const StatusCodes = require("node-opcua-status-code").StatusCodes;
const StatusCode = require("node-opcua-status-code").StatusCode;