Thank you very much for your review and kind words, @amosbastian!

The commits were made within a short time because I had a serious problem when syncing my folders in Dropbox between different PCs. I was annoyed and removed the old commits and rewrote them...

Regarding the create_xxx family, I am not quite sure how to refactor them. The current version should be convenient for users. Otherwise, let's wait and see their response :)

Your suggestions are very helpful. Thanks again!