Saving model objects

Hi, How do I process a click on a Save button with a Magrite built form? Using a manually created Seaside form I would register a callback, like: html anchor cssClass: 'btn btn-success'; callback: [ self save ]; with: 'Save' I understand that Magritte doesn't work directly on my model objects but rather with Mementos to process changes. I browsed the class hierarchy of MAMemento however it's not obvious how to make this work with my model. I use Voyage to persist my model objects in a Mongo database, so my model objects respond to the #save message. Ultimately I need to execute that method to persist changes. I suspect I need to implement a custom Memento subclass and somehow tie that to my model object but I'm not sure that is the right way. Maybe someone can shed some light on this? I've tried reading up on this but the various bits of documentation I found were lacking code samples. Thanks. Roger