Wait, if ManagerInstance is a singleton, then how can you run more than one server at the same time? Or are there two servers backed by the same cache manager?

I think we'll have to make ManagerInstance a regular class at some point, but perhaps it's worthy of a separate JIRA. On the other hand, if we don't change the tests now, we'll have even more code to change when we come around and implement that JIRA.