> How do you know anyone has ever read that code? Surely they read the lines they changed - that's where the problems were Of course. To fix an issue on a line

> How do you know anyone has ever read that code? Surely they read the lines they changed - that's where the problems were Of course. To fix an issue on a line, you need to know the context it’s used on and what happens with the line before and after. You also know what calls it or under what context. > did they necessarily read the lines they left alone? We can’t say for all of them, but they must have read lines that directly interact with it.