I need to change in runtime set of the series in polar chart, but I can't (exceptions).
https://fiddle.sencha.com/#view/editor&fiddle/1utv

How I can change set of the series?

Code:
Ext.application({
    name: 'Fiddle',


    launch: function () {
        Ext.create('Ext.panel.Panel', {


            controller: {
                loadSeries: function () {


                    var chart = this.getView().lookupReference('chart');
                    var store = chart.getStore();
                    store.loadData([{
                        name: '123',
                        data0: 4,
                        data1: 44
                    }, {
                        name: '234',
                        data0: 79,
                        data1: 33
                    }, {
                        name: '678',
                        data0: 79,
                        data1: 33
                    }, ]);


                    var series = [{
                        type: 'radar',
                        angleField: 'name',
                        radiusField: 'data0',
                    }, {
                        type: 'radar',
                        angleField: 'name',
                        radiusField: 'data2',
                    }];


                    chart.setSeries(series);
                },
            },


            renderTo: document.body,
            width: 300,
            height: 300,
            layout: 'card',
            buttons: [{
                text: 'load',
                handler: 'loadSeries',
            }],
            items: {
                xtype: 'polar',
                reference: 'chart',
                store: {


                    data: [],
                },


                sprites: [],
                axes: [{
                    type: 'numeric',
                    position: 'radial',
                    grid: true,
                    minimum: 0,
                    maximum: 100,


                }, {
                    type: 'category',
                    position: 'angular',
                    grid: true
                }],
                series: [{
                    angleField: "name",
                    radiusField: "data0",
                    title: "empty",
                    type: "radar"
                }, ]
            }


        });


    }
});