private static void pathto(World world, int i, int j, int k) {
   List<ChunkCoordinates> blocks = Lists.newLinkedList();
   List<ChunkCoordinates> portals = Lists.newLinkedList();
   List<ChunkCoordinates> repath = Lists.newLinkedList();
   List<ChunkCoordinates> redraw = Lists.newLinkedList();
   blocks.add(new ChunkCoordinates(i, j, k));
   while ((portals.size() > 0) || (blocks.size() > 0)) {
     while (blocks.size() > 0) {
       ChunkCoordinates coords = blocks.remove(0);
       directPortal(world, coords.posX + 1, coords.posY, coords.posZ, 5, blocks, portals);
       directPortal(world, coords.posX, coords.posY + 1, coords.posZ, 1, blocks, portals);
       directPortal(world, coords.posX, coords.posY, coords.posZ + 1, 3, blocks, portals);
       directPortal(world, coords.posX - 1, coords.posY, coords.posZ, 6, blocks, portals);
       directPortal(world, coords.posX, coords.posY - 1, coords.posZ, 2, blocks, portals);
       directPortal(world, coords.posX, coords.posY, coords.posZ - 1, 4, blocks, portals);
       redraw.add(coords);
     }
     if (portals.size() > 0) {
       ChunkCoordinates coords = portals.remove(0);
       directPortal(world, coords.posX + 1, coords.posY, coords.posZ, 5, blocks, portals);
       directPortal(world, coords.posX, coords.posY + 1, coords.posZ, 1, blocks, portals);
       directPortal(world, coords.posX, coords.posY, coords.posZ + 1, 3, blocks, portals);
       directPortal(world, coords.posX - 1, coords.posY, coords.posZ, 6, blocks, portals);
       directPortal(world, coords.posX, coords.posY - 1, coords.posZ, 2, blocks, portals);
       directPortal(world, coords.posX, coords.posY, coords.posZ - 1, 4, blocks, portals);
       if (world.getBlock(coords.posX, coords.posY, coords.posZ) == NailedBlocks.portal) {
         repath.add(coords);
       }
     }
   }
   while (repath.size() > 0) {
     ChunkCoordinates coords = repath.remove(0);
     if (world.getBlock(coords.posX, coords.posY, coords.posZ) == NailedBlocks.portal) {
       if (!BlockPortal.isValidPortal(world, coords.posX, coords.posY, coords.posZ)) {
         repathNeighbors(world, coords.posX, coords.posY, coords.posZ);
         world.setBlock(coords.posX, coords.posY, coords.posZ, Blocks.air, 0, 0);
         addSurrounding(repath, coords.posX, coords.posY, coords.posZ);
       } else {
         redraw.add(coords);
       }
     }
   }
   for (ChunkCoordinates coords : redraw) {
     if (world.blockExists(coords.posX, coords.posY, coords.posZ)) {
       world.markBlockForUpdate(coords.posX, coords.posY, coords.posZ);
       world.notifyBlocksOfNeighborChange(
           coords.posX,
           coords.posY,
           coords.posZ,
           world.getBlock(coords.posX, coords.posY, coords.posZ));
     }
   }
 }
 private static void depolarize(World world, int i, int j, int k, List<ChunkCoordinates> blocks) {
   Block block = world.getBlock(i, j, k);
   if (isValidLinkPortalBlock(block) == 0) {
     return;
   }
   if (world.getBlockMetadata(i, j, k) == 0) {
     return;
   }
   world.setBlockMetadataWithNotify(i, j, k, 0, 0);
   if ((block == NailedBlocks.portal) && (!BlockPortal.isValidPortal(world, i, j, k))) {
     world.setBlock(i, j, k, Blocks.air, 0, 2);
   }
   blocks.add(new ChunkCoordinates(i, j, k));
 }
 private static void onpulse(World world, int i, int j, int k) {
   List<ChunkCoordinates> set = Lists.newLinkedList();
   Stack<ChunkCoordinates> validate = new Stack<ChunkCoordinates>();
   addSurrounding(set, i, j, k);
   while (set.size() > 0) {
     ChunkCoordinates coords = set.remove(0);
     expandPortal(world, coords.posX, coords.posY, coords.posZ, set, validate);
   }
   while (validate.size() > 0) {
     ChunkCoordinates coords = validate.pop();
     i = coords.posX;
     j = coords.posY;
     k = coords.posZ;
     if (!BlockPortal.checkPortalTension(world, i, j, k)) {
       world.setBlock(i, j, k, Blocks.air, 0, 0);
     }
   }
 }