Since the first post about the NextGen modules some improvements have been done and some design choices have been done (the most important one is the params_lookup pattern which is the result of some good feedback and makes it possible to automatically retrieve class' arguments from top scope variables, an ENC and / or Hiera).

Here is some detailed documentation on the common arguments of the new modules:

And to make things, hopefully, clearer, here some sample usage code snippets: