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

endpointUrl: string | undefined,
  endpoint: EndpointDescription
): boolean {

    assert(endpoint instanceof EndpointDescription);
    const endpoint_securityPolicy = fromURI(endpoint.securityPolicyUri);
    if (endpointUrl && endpoint.endpointUrl! !== endpointUrl) {
        return false;
    }
    return (endpoint.securityMode === securityMode && endpoint_securityPolicy === securityPolicy);
}

const defaultSecurityModes = [
    MessageSecurityMode.None,
    MessageSecurityMode.Sign,
    MessageSecurityMode.SignAndEncrypt
];
const defaultSecurityPolicies = [
    SecurityPolicy.Basic128Rsa15,
    SecurityPolicy.Basic256,
// xx UNUSED!!    SecurityPolicy.Basic256Rsa15,
    SecurityPolicy.Basic256Sha256
];

endpointUrl: string | undefined,
  endpoint: EndpointDescription
): boolean {

    assert(endpoint instanceof EndpointDescription);
    const endpoint_securityPolicy = fromURI(endpoint.securityPolicyUri);
    if (endpointUrl && endpoint.endpointUrl! !== endpointUrl) {
        return false;
    }
    return (endpoint.securityMode === securityMode && endpoint_securityPolicy === securityPolicy);
}

const defaultSecurityModes = [
    MessageSecurityMode.None,
    MessageSecurityMode.Sign,
    MessageSecurityMode.SignAndEncrypt
];
const defaultSecurityPolicies = [
    SecurityPolicy.Basic128Rsa15,
    SecurityPolicy.Basic256,
// xx UNUSED!!    SecurityPolicy.Basic256Rsa15,
    SecurityPolicy.Basic256Sha256
];

endpoints = endpoints.filter((e: EndpointDescription) => {
        return e.securityMode === MessageSecurityMode.SignAndEncrypt;
    });