This annotation should be used on methods that need to be notified when a cache entry is expired
Methods annotated with this annotation should be public and take in a single parameter, a
will be thrown when registering your cache listener.
Locking: there is no guarantee as to whether the lock is acquired for this key, however there is internal
guarantees to make sure these events are not out of order
It is possible yet highly unlikely to receive this event right after a remove event even though the value
was previously removed. This can happen in the case when an expired entry in a store (not present in memory) is
found by the reaper thread and a remove occurs at the same time.