Question 3. (9 pts) The following class represents an interval of time between two Dates. public class Interval ( private Date start; private Date stop; private long duration; // Rep invariant: duration stop.getTime() - start.getTime() public Interval (Date start, Date stop) i this. start = start; this, stop = stop ; duration = stop. getTime() - start. getTime(); public Date getstart) f return start; 1 public Date getstop) l return stop; 1 public long getDuration ) l return duration; h Willy Wazoo argues that the rep invariant of Interval always holds, because duration is initialized once in the constructor, to the correct value. Give all reasons why Willy is wrong