Dispose() implementation

Hi, I’m currently using in my proyect a library that provides a dispose() method that I believe right now is never called, I instantiate objects of that library within the classes on my sketch, so I don’t know how exactly to call that dispose handler.
Shall I provide my classes with a dispose() method that calls the dispose handler of the objects belonging to that library; and register the dispose() method of my classes into PApplet by passing a reference to PApplet into the constructors of the classes and call PApplet.registerDispose(this);?
Is PApplet static (surely not) so that I can avoid passing it’s reference on the class constructor?