Java, how would I write a junit class for the update and toString methods?

AUsersthnDownloads Pokemon Trainer java Notepad. File Edit Search View Encoding Language Settings Tools Macro Run Plugins Window ppened 1import java.util.Observer 2 import java.util.observable public clasa PokesonTrainer implements Myobserver f private 3tring myiame einvariant nyName 18 19 25 publie PokemonTrainer (string name) { myNane namei public string getHame O return yName 34 36 37 eoverride 42 public void update (Myobservable oba, Object O) string whatHappened whatHappened - this is notified thato System.out-print.in (whatHappened) 47 18 51 E blic String tostringO ( string returnval returnval"PokenonTrainer " myName return returnval 54 56 7end class PokemonTzainer 50