I think the article was updated with that in response to my comment: > P.S. As pointed out by a fellow HackerNews reader, we clearly forgot to include our code

I think the article was updated with that in response to my comment: > P.S. As pointed out by a fellow HackerNews reader, we clearly forgot to include our code snippet for ControlNet in the article. No other code snippet besides the one added in response uses Canny, at least so far as I can see.