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// Theclass CalendarImplementation objectextends isCalendar a{
 concrete implementation of the abstract Calendar class// ...
}

// Class ForwardingCalendar
public class ForwardingCalendar {
  private final CalendarImplementation c;

  public ForwardingCalendar(CalendarImplementation c) {
    this.c = c;
  }

  CalendarImplementation getCalendarImplementation() {
    return c;
  }

  public boolean after(Object when) {
    return c.after(when);
  }

  public int compareTo(Calendar anotherCalendar) {
    // CalendarImplementation.compareTo() will be called
    return c.compareTo(anotherCalendar);
  }
}

class CompositeCalendar extends ForwardingCalendar {
  public CompositeCalendar(CalendarImplementation ci) {
    super(ci);
  }

  @Override public boolean after(Object when) {
    // This will call the overridden version, i.e. CompositeClass.compareTo();
    if (when instanceof Calendar && super.compareTo((Calendar)when) == 0) {
      // Return true if it is the first day of week
      return true;
    }
    return super.after(when); // Does not compare with first day of week any longer;
                              // Uses default comparison with epoch
  }

  @Override public int compareTo(Calendar anotherCalendar) {
    return compareDays(super.getCalendarImplementation().getFirstDayOfWeek(),
                       anotherCalendar.getFirstDayOfWeek());
  }

  private int compareDays(int currentFirstDayOfWeek, int anotherFirstDayOfWeek) {
    return (currentFirstDayOfWeek > anotherFirstDayOfWeek) ?
           1 : (currentFirstDayOfWeek == anotherFirstDayOfWeek) ? 0 : -1;
  }

  public static void main(String[] args) {
    CalendarImplementation ci1 = new CalendarImplementation();
    ci1.setTime(new Date());
    ci1.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY); // Date of last Sunday (before now)

    CalendarImplementation ci2 = new CalendarImplementation();
    CompositeCalendar c = new CompositeCalendar(ci1);
    System.out.println(c.after(ci2));                // expected to print true
  }
}