java 类的方法调用

public class PolyTester {public static void main(String[] args){bogo(new Extension());}static void bogo(Base b){b.add(8);b.print();}}class Base{int i;Base() {System.out.println("Base "+ i);add(1);}void add(int v){System.out.println("Base add"+ i);i+=v;}void print(){System.out.println(i);}}class Extension extends Base{Extension() {System.out.println("Extension"+ i);add(2);System.out.println("Extension"+ i);}void add(int v){System.out.println("Extension  add");i+=v*2;System.out.println("Extension  add"+ i);}}