@EventHandler(priority = EventPriority.HIGHEST, ignoreCancelled = true)
 public void onPistonRetract(BlockPistonRetractEvent event) {
   ZoneManager manager = m_plugin.getZoneManager();
   if (!manager.zoneExists(event.getBlock().getLocation())) {
     if (manager.zoneExists(event.getRetractLocation())) {
       event.setCancelled(true);
       return;
     }
   } else if (!manager
       .getZone(event.getBlock().getLocation())
       .getName()
       .equals(manager.getZone(event.getRetractLocation()).getName())) {
     event.setCancelled(true);
     return;
   }
 }