code: @Override
  	public boolean canMerge(ItemStack itemStack, EntityPlayer player, World world, BlockPos pos, EnumFacing side)
  	{
  		IBlockState state = world.getBlockState(pos);
  		if (isCorner(state))
  			return false;
  
  		return EnumFacingUtils.getRealSide(state, side) != EnumFacing.NORTH;
  	}
docs: Checks whether the block can be merged into a corner.
  
  @param itemStack the item stack
  @param player the player
  @param world the world
  @param pos the pos
  @param side the side
  @return true, if successful