test.js

(function () {
    'use strict';

    var List = Class({
        /**
         * @type {Array<string>}
         */
        _items: [],

        /**
         * @type {Object<HTMLElement>}
         */
        _itemNodes: {},

        /**
         * @param {Array<string>} items
         * @private
         */
        __construct: function (items) {
            this._items = items;
            this.node = mkE({tag: 'div'});
            this._render();
        },

        /**
         * @private
         */
        _render: function () {
            mkE.clearNode(this.node);
            for (var i in this._items) {
                var item = this._items[i];
                var itemNode = mkE({
                    tag: 'a',
                    text: item
                }).append(this.node);

                this._itemNodes[item] = node;
            }
        },

        /**
         * @param {Array<string>} items
         * @public
         */
        activate: function (items) {
            for (var i in items) {
                mkE.addClassName(this._itemNodes[items[i]], 'active');
            }
        }
    }, mkE.Base);

    var list = new List(['one', 'two', 'three']);
    list.append(document.body);
    list.activate(['one', 'two']);
})();