// Textbook fragment 02.16
public class Maryland extends State {
  Maryland() { /* null constructor */ }
  public void printMe() { System.out.println("Read it."); }
  public static void main(String[] args) {
    Region mid = new State();
    State md = new Maryland();
    Object obj = new Place();
    Place usa = new Region();
    md.printMe();
    mid.printMe();
    ((Place) obj).printMe();
    obj = md;
    ((Maryland) obj).printMe();
    obj = usa;
    ((Place) obj).printMe();
    usa = md;
    ((Place) usa).printMe();
  }
}
class State  extends Region {
  State() { /* null constructor */ }
  public void printMe() { System.out.println("Ship it."); }
}
class Region extends Place {
  Region() { /* null constructor */ }
  public void printMe() { System.out.println("Box it."); }
}
class Place extends Object {
  Place() { /* null constructor */ }
  public void printMe() { System.out.println("Buy it."); }
}