How to use the node-opcua-service-endpoints.UserTokenType.Anonymous function in node-opcua-service-endpoints

userIdentityTokens.push({
            policyId: "certificateX509",
            tokenType: UserTokenType.Certificate,

            issuedTokenType: null,
            issuerEndpointUrl: null,
            securityPolicyUri: null
        });

    }

    if (options.allowAnonymous) {

        userIdentityTokens.push({
            policyId: "anonymous",
            tokenType: UserTokenType.Anonymous,

            issuedTokenType: null,
            issuerEndpointUrl: null,
            securityPolicyUri: null
        });
    }

    // return the endpoint object
    const endpoint = new EndpointDescription({

        endpointUrl: options.endpointUrl,

        server: undefined, // options.server,
        serverCertificate: options.serverCertificateChain,

        securityMode: options.securityMode,

userIdentityTokens.push({
            policyId: "certificateX509",
            tokenType: UserTokenType.Certificate,

            issuedTokenType: null,
            issuerEndpointUrl: null,
            securityPolicyUri: null
        });

    }

    if (options.allowAnonymous) {

        userIdentityTokens.push({
            policyId: "anonymous",
            tokenType: UserTokenType.Anonymous,

            issuedTokenType: null,
            issuerEndpointUrl: null,
            securityPolicyUri: null
        });
    }

    // return the endpoint object
    const endpoint = new EndpointDescription({

        endpointUrl: options.endpointUrl,

        server: undefined, // options.server,
        serverCertificate: options.serverCertificateChain,

        securityMode: options.securityMode,

"discoveryUrls2",
                "discoveryUrls3",
                "discoveryUrls4",
                "discoveryUrls5"
            ]
        },

        serverCertificate: Buffer.alloc(256),

        securityMode: MessageSecurityMode.None,

        securityPolicyUri: "http://opcfoundation.org/UA/SecurityPolicy#Basic128Rsa15",
        userIdentityTokens: [
            {
                policyId: "policyId",
                tokenType: UserTokenType.Anonymous,
                issuedTokenType: "issuedTokenType",
                issuerEndpointUrl: "qdqsdq",
                securityPolicyUri: "String"
            }
        ],
        transportProfileUri: "",
        securityLevel: 36
    };
    var value = new EndpointDescription(data);
    assert(value.server);
    return value;
};