How to use the node-opcua-service-discovery.FindServersRequest function in node-opcua-service-discovery

return filename;
}

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

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

const endpoints_service = require("node-opcua-service-endpoints");
const GetEndpointsResponse = endpoints_service.GetEndpointsResponse;
const ApplicationType = endpoints_service.ApplicationType;

const OPCUASecureObject = require("node-opcua-common").OPCUASecureObject;


const discovery_service = require("node-opcua-service-discovery");
const FindServersRequest = discovery_service.FindServersRequest;
const FindServersResponse = discovery_service.FindServersResponse;
const LocalizedText = require("node-opcua-data-model").LocalizedText;

const default_server_info = {

    // The globally unique identifier for the application instance. This URI is used as
    // ServerUri in Services if the application is a Server.
    applicationUri: "urn:NodeOPCUA-Server-default",

    // The globally unique identifier for the product.
    productUri: "NodeOPCUA-Server",

    // A localized descriptive name for the application.
    applicationName: {text: "NodeOPCUA", locale: null},
    applicationType: ApplicationType.Server,
    gatewayServerUri: "",

OPCUAClientBase.prototype.getEndpointsRequest = function(options,callback) {
    console.log("note: OPCUAClientBase#getEndpointsRequest is deprecated, use OPCUAClientBase#getEndpoints instead");
    return this.getEndpoints(options,callback);
};

/**
 *
 * send a FindServers request to a discovery server
 * @method findServers
 * @async
 * @param callback [Function}
 */

const discovery_service = require("node-opcua-service-discovery");
const FindServersRequest = discovery_service.FindServersRequest;
const FindServersResponse = discovery_service.FindServersResponse;
const FindServersOnNetworkRequest = discovery_service.FindServersOnNetworkRequest;
const FindServersOnNetworkResponse = discovery_service.FindServersOnNetworkResponse;

/**
 * @method findServers
 * @param options
 * @param [options.endpointUrl]
 * @param [options.localeIds] Array
 * @param [options.serverUris] Array
 * @param callback
 */
OPCUAClientBase.prototype.findServers = function (options, callback) {

    const self = this;