Since we didn't have a way to clear the cache with this granularity before I thought it would be nice to only do this on demand.
I can imagine a situation where a user transitions from one page to another, and some models are re-used between the first and second pages. When the first page is unloaded, all models will have `release()` called. But then as the second page is loaded some models will be requested again, it would be wasteful to purge them from the store so optimistically. It would be better to wait for the second page to load, and then purge anything that is unused at that time.