The (deprecated) Marionette.Module Class as a standalone library.
In Marionette 1.x and 2.x the Application Class has a module method. To shim this behavior for v3.x
require('marionette.module').shim(Marionette);This will add Modules onto the application prototype.
If you would like to use the standalone Module Class you can
var Module = require('marionette.module');