@grkvlt for Group/Cluster using generics: haven't looked at it deeply. Intuitively it should be able to, which would cause a cascade of generics across the many sub-types of group/cluster.

Speaking of which, `EntitySpec.create` takes `Class` rather than `TypeToken` so would require looking at that before we could make use of generics properly.

p.s. before making a hell-of-a-lot-of-changes for generics here, if you're thinking of doing it then please e-mail brooklyn-dev first!