// Example 28 from page 23 of Java Precisely second edition (The MIT Press 2005) // Author: Peter Sestoft (sestoft@itu.dk) class Example28 { public static void main(String[] args) { Vessel v1 = new Barrel(3, 10); Vessel v2 = new Tank(10, 20, 12); Vessel v3 = new Cube(4); Vessel[] vs = { v1, v2, v3 }; v1.fill(90); v1.fill(10); v2.fill(100); v3.fill(80); double sum = 0; for (int i=0; i