this may no seem like an odd comment (please at least admire the pun), but generally I can see value in this. All this stuff is-even and is-number is doing to make sure that it is actually a number, throwing errors etc. pp. sure, I could do it myself, but I would probably miss half of the cases and would spend some time finding the right solutions for the other half. Why I should reinvent the wheel if someone already has, and that in a good and thought through way? Don't get me wrong, there are tons of needless packages on npm, but in this case I can see the value (ok, maybe the is-odd is one too much and !is-even would be enough)

just to to trigger a bit more: Pretty sure a case manufacturer could develop it's own screws... but I think in most cases they just use what someone else provides...