How can i write a new classifier in rapidminer ?

Hi, I need rocchio classifier in my classification task but did not found it already available in rapid miner. I saw a research paper and i think that writing own implementation of rocchio would not a very hefty task so i decided to write my own implementation for rocchio.

How can i write a new classifier which can work with example set ? Any parent class(to extends) or interfaces(to implement) i need for this purpose ?