// Textbook fragment 08.02
/** Comparator for 2D points under the standard lexicographic order. */
public class Lexicographic<E extends Point2D>
      implements java.util.Comparator<E> {
  /** Compare two points */
  public int compare(E a, E b) {
    if (a.getX() != b.getX())
      return b.getX() - a.getX();
    else
      return b.getY() - a.getY();
  }
} // Lexicographic automatically inherits an equals() method from Object