I would lean towards having almost anything like this be case sensitive unless explicitly told otherwise. It makes more sense to be case sensitive if you ask me. And the fact that it doesn't say to be case insensitive in the description and none of the tests (random or otherwise) require it to be case insensitive seems to support that.

I think it's a pretty good, concise and readable solution. The task doesn't state that anagrams are case-insensitive. I would only argue that it returns an iterator instead of a list. But casting the returned value to a list solves the issue.

Hello brother. It don't say case-insensitive.