Type of the cache entry.
Whether GC is idle.
Number of managed entries.
Clear all managed entries.
Leaves entry without expiration, by un-managing it.
Manage entry expiration.
Register callback invoked when entry expires.
Notify GC about expiration change of the managed entry.
GarbageCollector implementation which uses a map of buckets to keep entries that needs to be evicted.
Each timestamp has an according bucket with entries that need to be evicted at that time.
A timer is set to tick on each second and evicts all entries from the bucket corresponding to timestamp when timer fired.