pocketmine\event\entity\EntityLevelChangeEvent::getOrigin PHP Method

    public function getOrigin()
    {
        return $this->originLevel;
    }

 /**
  * @param EntityLevelChangeEvent $event
  *
  * @priority MONITOR
  */
 public function onEntityLevelChange(EntityLevelChangeEvent $event)
 {
     $entity = $event->getEntity();
     if ($entity instanceof Player) {
         $this->getPlugin()->switchLevelVanish($entity, $event->getOrigin(), $event->getTarget());
     }
 }