package com.oracle.java8.associate.test; abstract class Ball { protected final int size; public Ball(int size) { this.size = size; } } interface Equipment {} public class SoccerBall extends Ball implements Equipment { public SoccerBall() { super(5); } public Ball get() { return this; } public static void main(String[] args) { Equipment equipment = (Equipment) (Ball) new SoccerBall().get(); System.out.println(((SoccerBall) equipment).size); } }