/**
  * This function takes a set of proposed new events in. It looks for any duplicate events already saved and filters them out.
  * @return Array New proposed events where duplicates don't exist.
  */
 public function filterEventsForExisting(EventModel $sourceEvent, $events)
 {
     $group = new GroupModel();
     $group->setId($sourceEvent->getGroupId());
     $out = array();
     foreach ($events as $event) {
         $erb = new EventRepositoryBuilder();
         $erb->setGroup($group);
         $erb->setStart($event->getStartAt());
         $erb->setEnd($event->getEndAt());
         $existingEvents = $erb->fetchAll();
         if (count($existingEvents) > 0) {
         } else {
             $out[] = $event;
         }
     }
     return $out;
 }