private TileEntityFurnace getUsableFurnace(BlockIndex b) {
// reserve that furnace if found from the block reserve system
for (ForgeDirection dir : ForgeDirection.VALID_DIRECTIONS) {
BlockIndex index = new BlockIndex (b.x + dir.offsetX, b.y
+ dir.offsetY, b.z
+ dir.offsetZ);
if (robot.getRegistry().isTaken(new ResourceIdBlock(index))) {
continue;