private String[] readEvents() {
   List<String> strings = new ArrayList<String>();
   for (EventTransaction tr : persistence.getEventsFromFile()) {
     strings.add((String) tr.getEvent());
   }
   return strings.toArray(new String[] {});
 }
 private void addEvent(String stringEvent) {
   EventTransaction event = new EventTransaction((long) 0, stringEvent);
   persistence.writeEvent(event);
 }