import org.junit.Test;
import org.junit.Assert;

public class CashRegisterTest
{
   private static final double EPSILON = 1E-12;

   @Test public void twoPurchases()
   {
      CashRegister register = new CashRegister();
      register.recordPurchase(0.75);
      register.recordPurchase(1.50);
      register.receivePayment(2, 0, 5, 0, 0);
      double expected = 0.25;
      Assert.assertEquals(expected, register.giveChange(), EPSILON);
   }

   @Test public void testZeroBalance() 
   {
      CashRegister register = new CashRegister();
      register.recordPurchase(2.25);
      register.recordPurchase(19.25);
      register.receivePayment(21, 2, 0, 0, 0);
      Assert.assertEquals(0, register.giveChange(), EPSILON);
   }

   // More test cases 
   // . . .
}