How to use the pkcs11js.CKA_PRIVATE function in pkcs11js

v: number;
  /**
   * Type of Attribute
   */
  t: AttributeItemType;
}

interface IAttributeItems {
  [key: string]: IAttributeItem;
}

const attribute: IAttributeItems = {
  /* The following attribute types are defined: */
  class: { v: pkcs11.CKA_CLASS, t: TYPE_NUMBER },
  token: { v: pkcs11.CKA_TOKEN, t: TYPE_BOOL },
  private: { v: pkcs11.CKA_PRIVATE, t: TYPE_BOOL },
  label: { v: pkcs11.CKA_LABEL, t: TYPE_STRING },
  application: { v: pkcs11.CKA_APPLICATION, t: TYPE_STRING },
  value: { v: pkcs11.CKA_VALUE, t: TYPE_BUFFER },

  /* CKA_OBJECT_ID is new for v2.10 */
  objectId: { v: pkcs11.CKA_OBJECT_ID, t: TYPE_BUFFER },

  certType: { v: pkcs11.CKA_CERTIFICATE_TYPE, t: TYPE_NUMBER },
  issuer: { v: pkcs11.CKA_ISSUER, t: TYPE_BUFFER },
  serial: { v: pkcs11.CKA_SERIAL_NUMBER, t: TYPE_BUFFER },

  /* CKA_AC_ISSUER, CKA_OWNER, and CKA_ATTR_TYPES are new
 * for v2.10 */
  issuerAC: { v: pkcs11.CKA_AC_ISSUER, t: TYPE_BUFFER },
  owner: { v: pkcs11.CKA_OWNER, t: TYPE_BUFFER },
  attrTypes: { v: pkcs11.CKA_ATTR_TYPES, t: TYPE_BUFFER },

_pkcs11CreateObject(pkcs11, pkcs11Session, key, pkcs11Token) {
		const ski = this._ski();
		const keyTemplate = [
			{type: pkcs11js.CKA_ID, value: ski},
			{type: pkcs11js.CKA_CLASS, value: pkcs11js.CKO_SECRET_KEY},
			{type: pkcs11js.CKA_KEY_TYPE, value: pkcs11js.CKK_AES},
			// SoftHSMv2 prohibits specifying CKA_VALUE_LEN
			// { type: pkcs11js.CKA_VALUE_LEN, value: key.length },
			{type: pkcs11js.CKA_VALUE, value: key},
			{type: pkcs11js.CKA_ENCRYPT, value: true},
			{type: pkcs11js.CKA_DECRYPT, value: true},
			{type: pkcs11js.CKA_PRIVATE, value: this._pkcs11Login},
			{type: pkcs11js.CKA_TOKEN, value: this._pkcs11Login && pkcs11Token}
		];

		const handle = pkcs11.C_CreateObject(pkcs11Session, keyTemplate);
		return {ski, key: handle};
	}

* Call PKCS11 API to generate the key.
			*/
		const handle = pkcs11.C_GenerateKey(
			pkcs11Session, {mechanism: pkcs11js.CKM_AES_KEY_GEN},
			secretKeyTemplate);
		/*
			* Template for querying key attributes (debug only).
			*/
		const objectTemplate = [
			{type: pkcs11js.CKA_ID},
			{type: pkcs11js.CKA_CLASS},
			{type: pkcs11js.CKA_KEY_TYPE},
			{type: pkcs11js.CKA_VALUE_LEN},
			{type: pkcs11js.CKA_ENCRYPT},
			{type: pkcs11js.CKA_DECRYPT},
			{type: pkcs11js.CKA_PRIVATE},
			{type: pkcs11js.CKA_TOKEN}
		];
		logger.debug(__func() + 'secretKey: ' + util.inspect(
			this._pkcs11GetAttributeValue(
				pkcs11, pkcs11Session, handle, objectTemplate),
			{depth: null}));

		return {ski, key: handle};
	}

"use strict";
var pkcs11 = require("pkcs11js");
var TYPE_NUMBER = "number";
var TYPE_BOOL = "boolen";
var TYPE_STRING = "string";
var TYPE_BUFFER = "buffer";
var TYPE_DATE = "date";
var attribute = {
    class: { v: pkcs11.CKA_CLASS, t: TYPE_NUMBER },
    token: { v: pkcs11.CKA_TOKEN, t: TYPE_BOOL },
    private: { v: pkcs11.CKA_PRIVATE, t: TYPE_BOOL },
    label: { v: pkcs11.CKA_LABEL, t: TYPE_STRING },
    application: { v: pkcs11.CKA_APPLICATION, t: TYPE_STRING },
    value: { v: pkcs11.CKA_VALUE, t: TYPE_BUFFER },
    objectId: { v: pkcs11.CKA_OBJECT_ID, t: TYPE_BUFFER },
    certType: { v: pkcs11.CKA_CERTIFICATE_TYPE, t: TYPE_NUMBER },
    issuer: { v: pkcs11.CKA_ISSUER, t: TYPE_BUFFER },
    serial: { v: pkcs11.CKA_SERIAL_NUMBER, t: TYPE_BUFFER },
    issuerAC: { v: pkcs11.CKA_AC_ISSUER, t: TYPE_BUFFER },
    owner: { v: pkcs11.CKA_OWNER, t: TYPE_BUFFER },
    attrTypes: { v: pkcs11.CKA_ATTR_TYPES, t: TYPE_BUFFER },
    trusted: { v: pkcs11.CKA_TRUSTED, t: TYPE_BOOL },
    certCategory: { v: pkcs11.CKA_CERTIFICATE_CATEGORY, t: TYPE_NUMBER },
    javaDomain: { v: pkcs11.CKA_JAVA_MIDP_SECURITY_DOMAIN, t: TYPE_NUMBER },
    url: { v: pkcs11.CKA_URL, t: TYPE_STRING },
    ski: { v: pkcs11.CKA_HASH_OF_SUBJECT_PUBLIC_KEY, t: TYPE_BUFFER },
    aki: { v: pkcs11.CKA_HASH_OF_ISSUER_PUBLIC_KEY, t: TYPE_BUFFER },