Webform custom composite Could someone advise on how to adopt the working composite example that comes with Webform in Drupal 8?

https://www.drupal.org/node/2824714 suggests it can be done.

I've copied the example from modules/webform/modules/webform_example_composite folder. Does this need to go into the webform root folder with other example or root module folder? 

I realise that the functions and iterations of webform_example_composite need to be renamed.

I also tried altering the pr-existing example that comes with Webform, without success.
Someone very kindly posted an example https://www.drupal.org/node/2883734.
Module creator also suggested here https://www.drupal.org/node/2824714 that documentation is being updated.