JSFiddle - React, Tailwind, and code Playground

JavaScript

require([
    'dojo/_base/declare',
    'dojo/Stateful'
], function(declare, Stateful) {
    
    var Obj = declare([Stateful], {
        foo: function() {
            return "original foo";
        }
    });
    
    var o = new Obj({
        foo: function() {
            return "no way";
        }
    });
    
    console.log(o.foo());
});