ch02/rectangles/RectangleComponent.java
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Rectangle;
 import javax.swing.JComponent;

 /**
 A component that draws two rectangles.
 */
 public class RectangleComponent extends JComponent
 {
 public void paintComponent(Graphics g)
 {
 // RecoverGraphics2D
 Graphics2D g2 = (Graphics2D) g;

 // Construct a rectangle and draw it
 Rectangle box = new Rectangle(5, 10, 20, 30);
 g2.draw(box);

 // Move rectangle 15 units to the right and 25 units down
 box.translate(15, 25);

 // Draw moved rectangle
 g2.draw(box);
 }
 }