title: What are the eviction rule for apollo-cache-inmemory?
body: <p>From what I understand, anything in cache is ephemeral and is subjected to some kind of eviction rule, like LRU.  In this case, if we are using the in-memory cache and apollo-link-state to replace redux or vuex, how do we guarantee that some states don't get evicted in the middle of running the application?</p>