I'd like folders for my other calendars so I can toggle them all at once.

For example, I'd like to have a folder called "Work" under which 3 calendars reside and have one button which toggles them all on and off.

I have multiple calendars from other people which are useful to view but otherwise clutter my calendar too much, so I often have to go and enable/disable many calendars in bulk, even though I basically want to just toggle the set of "calendars for this person/theme".