The goal of this design pattern is to keep configurable data in one place and make it friendly to an ENC. This addresses the problem of module reusability. If you have are keeping data in your module, then someone else cannot just reuse your module without making changes to the code. This pattern solves that problem allowing for reusable modules.
A best practice is to have a module named 'common' that contains code that is used by all of your nodes. This class is then included in all of your nodes.