code: private World world(IBlockAccess world)
  	{
  		if (world instanceof World)
  			return (World) world;
  		else if (world instanceof ChunkCache)
  			return ((ChunkCache) world).world;
  
  		if (!FMLClientHandler.instance().hasOptifine())
  			return null;
  		if (chunkCacheClass == null || chunkCacheField != null)
  			return null;
  		if (!chunkCacheClass.isAssignableFrom(world.getClass()))
  			return null;
  
  		return world(Silenced.get(() -> ((ChunkCache) chunkCacheField.get(world))));
  	}
docs: Gets the actual world object based on the passed {@link IBlockAccess}.
  
  @param world the world
  @return the world