Is it a typo ? shelfs versus shelves

[LLyaudet]

Hello,

In some places in the repository, there is the plural word "shelfs" that I cannot find in a dictionary.
When I saw the error by the language linter in my IDE, I corrected to shelves.
But since it is library code, I thought that maybe you would like to correct it in case it is indeed a typo.
Let me know if you need a PR.

Best regards,
Laurent Lyaudet