Container exercise  *  * @author aguo
 * Exercise 13: (3) In the innerclasses/GreenhouseController.java example, the
class Controller uses an ArrayList. Change the code to use a LinkedList instead, and use
an Iterator to cycle through the set of events.
* 
* please refer to GreenhouseController.java
*   //private Iterator<Event> eventIterator = exerciseEventList.iterator();
  /*
   cause error:
   * Exception in thread "main" java.util.ConcurrentModificationException
	at java.util.LinkedList$ListItr.checkForComodification(LinkedList.java:761)
	at java.util.LinkedList$ListItr.next(LinkedList.java:696)
[containers.exercises.ExerciseThirteen$2@2f9ee1ac, containers.exercises.ExerciseThirteen$2@67f1fba0, containers.exercises.ExerciseThirteen$2@3fbefab0, containers.exercises.ExerciseThirteen$2@133c5982, containers.exercises.ExerciseThirteen$2@5f186fab, containers.exercises.ExerciseThirteen$2@3d4b7453, containers.exercises.ExerciseThirteen$2@24c21495, containers.exercises.ExerciseThirteen$2@41d5550d, containers.exercises.ExerciseThirteen$2@1cc2ea3f, containers.exercises.ExerciseThirteen$2@40a0dcd9]
	at containers.exercises.ExerciseThirteen.run(ExerciseThirteen.java:43)
	at containers.exercises.ExerciseThirteen.main(ExerciseThirteen.java:87)
Java Result: 1
and a question from the Controller.java    
  private List<Event> eventList = new ArrayList<Event>();
  public void addEvent(Event c) { eventList.add(c); }
  public void run() {
    while(eventList.size() > 0)
      // Make a copy so you're not modifying the list
      // while you're selecting the elements in it:
      for(Event e : new ArrayList<Event>(eventList))//if here doesn't use a copy of the List, currentModification error maybe pop up