// patterns/shapes/Shape.java // (c)2020 MindView LLC: see Copyright.txt // We make no guarantees that this code is fit for any purpose. // Visit http://OnJava8.com for more book information. package patterns.shapes; public class Shape { private static int counter = 0; private int id = counter++; @Override public String toString() { return getClass().getSimpleName() + "[" + id + "]"; } public void draw() { System.out.println(this + " draw"); } public void erase() { System.out.println(this + " erase"); } }