How to update objects inside a group in fabric JS

Fabric JS is an awesome javascript library for manipulating HTML5 canvas and it uses the groups functionality that can group objects inside it as one but the issue I stumbled before is when I try to update a location of an object inside a group it doesn’t work and the solution is setting to true the dirty property of a group, take a look of an example below

Here’s a complete working example how setting the dirty property works