public final void update(Level level, int x, int y, int z, Random rand) {
      int var6 = level.getTile(x, y - 1, z);
      if(level.isLit(x, y, z) && (var6 == Block.DIRT.id || var6 == Block.GRASS.id)) {
         if(rand.nextInt(5) == 0) {
            level.setTileNoUpdate(x, y, z, 0);
            if(!level.maybeGrowTree(x, y, z)) {
               level.setTileNoUpdate(x, y, z, this.id);
            }
         }

      } else {
         level.setTile(x, y, z, 0);
      }
   }