ch06/invest2/InvestmentRunner.java
 /**
 This program computes how much an investment grows in
 a given number of years.
 */
 public class InvestmentRunner
 {
 public static void main(String[] args)
 {
 final double INITIAL_BALANCE = 10000;
 final double RATE = 5;
 final int YEARS = 20;
 Investment invest = new Investment(INITIAL_BALANCE, RATE);
 invest.waitYears(YEARS);
 double balance = invest.getBalance();
 System.out.printf("The balance after %d years is %.2f\n",
 YEARS, balance);
 }
 }