Deleting the calendar named /tasks/ is disallowed.

At least one additional calendar must exist (otherwise deletion is forbidden).

Everything else is super flaky. Creating a calendar works, but it is sometimes not available for a while (I've tested sleeping 10 seconds, but that's not enough).

Renaming a collection doesn't seem to have any effect.

Creating events in calendars doesn't seem to work; just an opaque 404.