Similar to Method Overriding in Java, how to override the method about Box2d

beginContact() is a method of box2d Library.

I want to use it in processing.py. Due to the difference between java and python, the error comes out:
You are missing the beginContact() method. java.lang.NoSuchMethodException: jycessing.PAppletJythonDriver.beginContact(org.jbox2d.dynamics.contacts.Contact)

I use the box2d.listenForCollisions(), but it can’t find the beginContact() that I have written.

The raw tutorial code:Box2D-for-Processing/CollisionListeningDeletionExercise.pde at master · shiffman/Box2D-for-Processing · GitHub

It’s like some problem of write method Overriding from java into python

The tutorial taught that the beginContact() is used like mousePressed() method.