public List<MapleMapObject> getAllMechDoorsThreadsafe() {
        ArrayList<MapleMapObject> ret = new ArrayList<>();
        mapobjectlocks.get(MapleMapObjectType.DOOR).readLock().lock();
        try {
            for (MapleMapObject mmo : mapobjects.get(MapleMapObjectType.DOOR).values()) {
                if (mmo instanceof MechDoor) {
                    ret.add(mmo);
                }
            }
        } finally {
            mapobjectlocks.get(MapleMapObjectType.DOOR).readLock().unlock();
        }
        return ret;
    }