code: @SideOnly(Side.CLIENT)
  	public static void registerBlockRenderer(Block block, IBlockRenderer renderer)
  	{
  		clientRegistry.blockRenderers.put(checkNotNull(block), checkNotNull(renderer));
  		Item item = Item.getItemFromBlock(block);
  		if (item != null)
  			clientRegistry.itemRenderers.put(item, renderer);
  	}
docs: Registers a {@link IBlockRenderer} for the {@link Block}, and its {@link Item} if any.
  
  @param block the block
  @param renderer the renderer