The source code that you are referring to is an old version. Later, these moved to different repositories and changed.
For example, you can find `generateUUID` here:
Hi Sachin,
You might wanna have a look at these Forum posts,
https://community.mendix.com/link/space/widgets/questions/105360
https://community.mendix.com/link/space/widgets/questions/114870
https://community.mendix.com/link/space/widgets/questions/101371
Hope these answers help you to resolve your issue...