public void update(Level level, int x, int y, int z, Random rand) {
      if(!level.growTrees) {
         int var6 = level.getTile(x, y - 1, z);
         if(!level.isLit(x, y, z) || var6 != Block.DIRT.id && var6 != Block.GRASS.id) {
            level.setTile(x, y, z, 0);
         }

      }
   }