public class WorldGenBurnedTree extends WorldGenAbstractTree{

    public WorldGenBurnedTree(boolean notify) {
          super(notify);
        }

        public static final IBlockState TRUNK = BlockInit.BURNED_LOG.getDefaultState();

        public boolean generate(World worldIn, Random rand, BlockPos base) {
            int trunkHeight = rand.nextInt(4) + 3;

            for (int i = 0; i < trunkHeight; i++) {
                if (!(worldIn.getBlockState(new BlockPos(base.getX(), base.getY() + i + 1, base.getZ())).equals(Blocks.AIR.getDefaultState()))) {
                    return false;
                }
            }
            for (int i = 0; i < trunkHeight; i++) {
              world.setBlockState(new BlockPos(base.getX(), base.getY() + i + 1, base.getZ()), TRUNK);
            }
        }
}