Basic locking grid, + cookie provider.

Code:
Ext.require([
    'Ext.grid.*',
    'Ext.data.*',
    'Ext.util.*',
    'Ext.state.*'
]);

Ext.onReady(function() {
    Ext.QuickTips.init();

    // sample static data for the store
    var myData = [
        ['3m Co',                               71.72, 0.02,  0.03,  '9/1 12:00am'],
        ['Alcoa Inc',                           29.01, 0.42,  1.47,  '9/1 12:00am'],
        ['Altria Group Inc',                    83.81, 0.28,  0.34,  '9/1 12:00am'],
        ['American Express Company',            52.55, 0.01,  0.02,  '9/1 12:00am'],
        ['American International Group, Inc.',  64.13, 0.31,  0.49,  '9/1 12:00am'],
        ['AT&T Inc.',                           31.61, -0.48, -1.54, '9/1 12:00am'],
        ['Boeing Co.',                          75.43, 0.53,  0.71,  '9/1 12:00am'],
        ['Caterpillar Inc.',                    67.27, 0.92,  1.39,  '9/1 12:00am'],
        ['Citigroup, Inc.',                     49.37, 0.02,  0.04,  '9/1 12:00am'],
        ['E.I. du Pont de Nemours and Company', 40.48, 0.51,  1.28,  '9/1 12:00am'],
        ['Exxon Mobil Corp',                    68.1,  -0.43, -0.64, '9/1 12:00am'],
        ['General Electric Company',            34.14, -0.08, -0.23, '9/1 12:00am'],
        ['General Motors Corporation',          30.27, 1.09,  3.74,  '9/1 12:00am'],
        ['Hewlett-Packard Co.',                 36.53, -0.03, -0.08, '9/1 12:00am'],
        ['Honeywell Intl Inc',                  38.77, 0.05,  0.13,  '9/1 12:00am'],
        ['Intel Corporation',                   19.88, 0.31,  1.58,  '9/1 12:00am'],
        ['International Business Machines',     81.41, 0.44,  0.54,  '9/1 12:00am'],
        ['Johnson & Johnson',                   64.72, 0.06,  0.09,  '9/1 12:00am'],
        ['JP Morgan & Chase & Co',              45.73, 0.07,  0.15,  '9/1 12:00am'],
        ['McDonald\'s Corporation',             36.76, 0.86,  2.40,  '9/1 12:00am'],
        ['Merck & Co., Inc.',                   40.96, 0.41,  1.01,  '9/1 12:00am'],
        ['Microsoft Corporation',               25.84, 0.14,  0.54,  '9/1 12:00am'],
        ['Pfizer Inc',                          27.96, 0.4,   1.45,  '9/1 12:00am'],
        ['The Coca-Cola Company',               45.07, 0.26,  0.58,  '9/1 12:00am'],
        ['The Home Depot, Inc.',                34.64, 0.35,  1.02,  '9/1 12:00am'],
        ['The Procter & Gamble Company',        61.91, 0.01,  0.02,  '9/1 12:00am'],
        ['United Technologies Corporation',     63.26, 0.55,  0.88,  '9/1 12:00am'],
        ['Verizon Communications',              35.57, 0.39,  1.11,  '9/1 12:00am'],
        ['Wal-Mart Stores, Inc.',               45.45, 0.73,  1.63,  '9/1 12:00am']
    ];

    /**
     * Custom function used for column renderer
     * @param {Object} val
     */
    function change(val) {
        if (val > 0) {
            return '<span style="color:green;">' + val + '</span>';
        } else if (val < 0) {
            return '<span style="color:red;">' + val + '</span>';
        }
        return val;
    }

    /**
     * Custom function used for column renderer
     * @param {Object} val
     */
    function pctChange(val) {
        if (val > 0) {
            return '<span style="color:green;">' + val + '%</span>';
        } else if (val < 0) {
            return '<span style="color:red;">' + val + '%</span>';
        }
        return val;
    }

    // create the data store
    var store = Ext.create('Ext.data.ArrayStore', {
        fields: [
           {name: 'company'},
           {name: 'price',      type: 'float'},
           {name: 'change',     type: 'float'},
           {name: 'pctChange',  type: 'float'},
           {name: 'lastChange', type: 'date', dateFormat: 'n/j h:ia'}
        ],
        data: myData
    });

    Ext.state.Manager.setProvider(Ext.create('Ext.state.CookieProvider'));
    // create the Grid
    var grid = Ext.create('Ext.grid.Panel', {
        stateId : 'fo',
        stateful : true,
        store: store,
        columnLines: true,
        columns: [{
            text     : 'Company<br>Name', // Two line header! Test header height synchronization!
            locked   : true,
            width    : 200,
            sortable : false,
            dataIndex: 'company'
        },{
            text     : 'Price',
            width    : 125,
            sortable : true,
            renderer : 'usMoney',
            dataIndex: 'price'
        },{
            text     : 'Change',
            width    : 125,
            sortable : true,
            renderer : change,
            dataIndex: 'change'
        },{
            text     : '% Change',
            width    : 125,
            sortable : true,
            renderer : pctChange,
            dataIndex: 'pctChange'
        },{
            text     : 'Last Updated',
            width    : 135,
            sortable : true,
            renderer : Ext.util.Format.dateRenderer('m/d/Y'),
            dataIndex: 'lastChange'
        }],
        height: 350,
        width: 600,
        title: 'Locking Grid Column',
        renderTo: 'grid-example',
        viewConfig: {
            stripeRows: true
        }
    });
});
toMap method expects an array as first argument. lockedHeaderCt.items is a MixedCollection...
Code:
applyColumnsState: function (columns) {
var me = this,
lockedGrid = me.lockedGrid,
lockedHeaderCt = lockedGrid.headerCt,
normalHeaderCt = me.normalGrid.headerCt,
lockedCols = Ext.Array.toMap(lockedHeaderCt.items, 'headerId'),
normalCols = Ext.Array.toMap(normalHeaderCt.items, 'headerId'),