MaskBlock codes?

Hello:

When you define a MaskBlock with “codes=,” where do the pixel-index and pixel-label from the “codes.txt” store?

I look in (example) “camvid.item_tfms”, but I couldn’t find it. I am doing my own project (not using camvid data), and I want to verify that the pixel-label read correctly.

Any help will be greatly appreciated.

e.g.
camvid = DataBlock(blocks=(ImageBlock, MaskBlock(codes = np.loadtxt(path/‘codes.txt’, dtype=str))),