One of the things I like most about this is that Ian includes the simple mistake in the first function. It’s a bit humbling and acknowledges the fact that even

One of the things I like most about this is that Ian includes the simple mistake in the first function. It’s a bit humbling and acknowledges the fact that even the best of us often make trivial mistakes. It also helps make the point that even the simplest code needs a basic test and adds another argument in favor of generics on the premise of duplicating tests.