How to use the node-opcua-secure-channel.SecurityPolicy function in node-opcua-secure-channel

module.exports.historizing_service = require("node-opcua-service-history");
module.exports.discovery_service = require("node-opcua-service-discovery");
module.exports.secure_channel_service = require("node-opcua-service-secure-channel");

module.exports.translate_browse_paths_to_node_ids_service = require("node-opcua-service-translate-browse-path");
module.exports.BrowsePath = require("node-opcua-service-translate-browse-path").BrowsePath;
module.exports.makeRelativePath = require("node-opcua-service-translate-browse-path").makeRelativePath;
module.exports.makeBrowsePath = require("node-opcua-service-translate-browse-path").makeBrowsePath;

module.exports.query_service = require("node-opcua-service-query");
module.exports.node_managment_service = require("node-opcua-service-node-management");

module.exports.ServerState = require("node-opcua-common").ServerState;
module.exports.ServiceCounter = require("node-opcua-common").ServiceCounter;

module.exports.SecurityPolicy = require("node-opcua-secure-channel").SecurityPolicy;
module.exports.MessageSecurityMode = require("node-opcua-service-secure-channel").MessageSecurityMode;

module.exports.utils = require("node-opcua-utils");
module.exports.crypto_utils = require("node-opcua-crypto");
module.exports.hexDump = require("node-opcua-debug").hexDump;

//----------------------------------------------------------------------------------------------------------------------
// client services
//----------------------------------------------------------------------------------------------------------------------
module.exports.OPCUAClient = require("node-opcua-client").OPCUAClient;
module.exports.OPCUAClientBase = require("node-opcua-client").OPCUAClientBase;

module.exports.NodeCrawler = require("node-opcua-client-crawler").NodeCrawler;
module.exports.ClientSubscription = require("node-opcua-client").ClientSubscription;
module.exports.ClientSession = require("node-opcua-client").ClientSession;

const fs = require("fs");
const path = require("path");
const async = require("async");
const _ = require("underscore");
const assert = require("node-opcua-assert").assert;
const once = require("once");
const delayed = require("delayed");


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

const GetEndpointsRequest = endpoints_service.GetEndpointsRequest;
const GetEndpointsResponse = endpoints_service.GetEndpointsResponse;
const MessageSecurityMode = require("node-opcua-service-secure-channel").MessageSecurityMode;
const toURI = require("node-opcua-secure-channel").toURI;
const SecurityPolicy = require("node-opcua-secure-channel").SecurityPolicy;

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

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

const ClientSecureChannelLayer = require("node-opcua-secure-channel/src/client/client_secure_channel_layer").ClientSecureChannelLayer;
const ClientSession = require("./client_session").ClientSession;


const defaultConnectionStrategy = {
    initialDelay: 1000,
    maxDelay: 20*1000,// 20 seconds
    maxRetry: -1, // infinite
    randomisationFactor: 0.1
};

const assert = require("node-opcua-assert").assert;
const async = require("async");
const EventEmitter = require("events").EventEmitter;
const util = require("util");
const _ = require("underscore");

const discovery_service = require("node-opcua-service-discovery");
const RegisterServerRequest = discovery_service.RegisterServerRequest;
const RegisterServerResponse = discovery_service.RegisterServerResponse;
const RegisterServer2Request = discovery_service.RegisterServer2Request;
const RegisterServer2Response = discovery_service.RegisterServer2Response;

const OPCUAClientBase = require("node-opcua-client").OPCUAClientBase;
const SecurityPolicy = require("node-opcua-secure-channel").SecurityPolicy;
const coerceSecurityPolicy = require("node-opcua-secure-channel").coerceSecurityPolicy;

const MessageSecurityMode = require("node-opcua-service-secure-channel").MessageSecurityMode;
const _enumerationMessageSecurityMode = require("node-opcua-service-secure-channel")._enumerationMessageSecurityMode;

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

const RegisterServerManagerStatus = new Enum({
    INACTIVE: 1,
    INITIALIZING: 2,
    REGISTERING: 3,
    WAITING: 4,
    UNREGISTERING: 5
});

/**
 * @module opcua.server
 */

const assert = require("node-opcua-assert").assert;
const async = require("async");
const util = require("util");
const fs = require("fs");
const _ = require("underscore");

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

const StatusCodes = require("node-opcua-status-code").StatusCodes;
const SessionContext = require("node-opcua-address-space").SessionContext;
const fromURI = require("node-opcua-secure-channel").fromURI;
const SecurityPolicy = require("node-opcua-secure-channel").SecurityPolicy;

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

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

const ServerEngine = require("./server_engine").ServerEngine;


const browse_service = require("node-opcua-service-browse");
const read_service = require("node-opcua-service-read");
const write_service = require("node-opcua-service-write");
const historizing_service = require("node-opcua-service-history");
const subscription_service = require("node-opcua-service-subscription");
const translate_service = require("node-opcua-service-translate-browse-path");

const session_service = require("node-opcua-service-session");
const AnonymousIdentityToken = session_service.AnonymousIdentityToken;
const CreateSessionRequest = session_service.CreateSessionRequest;
const CreateSessionResponse = session_service.CreateSessionResponse;
const ActivateSessionRequest = session_service.ActivateSessionRequest;
const ActivateSessionResponse = session_service.ActivateSessionResponse;
const CloseSessionRequest = session_service.CloseSessionRequest;

const endpoints_service = require("node-opcua-service-endpoints");
const ApplicationDescription = endpoints_service.ApplicationDescription;
const ApplicationType = endpoints_service.ApplicationType;
const EndpointDescription = endpoints_service.EndpointDescription;
const MessageSecurityMode = require("node-opcua-service-secure-channel").MessageSecurityMode;

const SecurityPolicy = require("node-opcua-secure-channel").SecurityPolicy;
const getCryptoFactory = require("node-opcua-secure-channel").getCryptoFactory;
const fromURI = require("node-opcua-secure-channel").fromURI;

const crypto_utils = require("node-opcua-crypto");
const UserNameIdentityToken = session_service.UserNameIdentityToken;


const buffer_utils = require("node-opcua-buffer-utils");
const createFastUninitializedBuffer = buffer_utils.createFastUninitializedBuffer;

const UserIdentityTokenType = require("node-opcua-service-endpoints").UserIdentityTokenType;

const ClientSession = require("./client_session").ClientSession;

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