JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://extjs.cachefly.net/ext/gpl/5.1.0/build/ext-all-debug.js"></script>
<script src="https://extjs.cachefly.net/ext/gpl/5.1.0/packages/ext-theme-neptune/build/ext-theme-neptune.js"></script>
<link rel="stylesheet" href="https://extjs.cachefly.net/ext/gpl/5.1.0/packages/ext-theme-neptune/build/resources/ext-theme-neptune-all-debug.css">
<script src="https://extjs.cachefly.net/ext/gpl/5.1.0/packages/sencha-charts/build/sencha-charts-debug.js"></script>
<link rel="stylesheet" href="https://extjs.cachefly.net/ext/gpl/5.1.0/packages/sencha-charts/build/neptune/resources/sencha-charts-all-debug.css">

JavaScript

Ext.application({
    name : 'Fiddle',

    launch : function() {
        Ext.define('User', {
            extend: 'Ext.data.Model',
            fields: [
                {name: 'firstName', type: 'string'},
                {name: 'lastName',  type: 'string'},
                {name: 'age',       type: 'int'},
                {name: 'eyeColor',  type: 'string'}
            ]
        });
        var store = Ext.create('Ext.data.Store', {
            model: 'User',
            groupField: 'firstName',
     		data : [
                {firstName: 'Ed',    lastName: 'Spencer'},
        	 	{firstName: 'Tommy', lastName: 'Maintz'},
                {firstName: 'Aaron', lastName: 'Conran'},
		        {firstName: 'Jamie', lastName: 'Avins'}
     		]
        });
        var firstGroupName = store.getGroups().getAt(0).getGroupKey();
        Ext.Msg.alert('Fiddle', 'First group name is ' + firstGroupName);
    }
});