import objectdraw.*;

/*
 * An empty stack of VisibleImages.  This implements the stack
 * interface, but only the isEmpty method should be used.
 */
public class EmptyStack implements StackInterface {

  public EmptyStack() {
  }

  public boolean isEmpty() {
    return true;
  }

  // return null as a default value
  public VisibleImage getFirst() {
    return null;
  }

  // return null as a default value
  public StackInterface getRest() {
    return null;
  }

}