I know this class was here before, but should it be? This seems like something used as a selector for unit tests and there is an entry in customstyles.css from fundamental-styles. It's fine to use some custom styles for a playground or such, but it shouldn't be part of the base component's classes.

Good catch! I'll remove it

@greg-a-smith turns out that entire div was just for the styles docs site. I'm removing it here and going to make a pr there to make that more obvious.