Priority + Expiration + LRU Eviction

Implement `evictItem()` for a cache-like class that already has `set(key, value, priority, expiretime)` and `get(key)`. Expired items are evicted first; otherwise lowest priority wins; ties break by least-recently-used. Requirements Class has existing black-box methods: set(key, value, priority, expiretime) and get(key). Implement evictItem() only. Each item has key, value, priority, and expiretime. Eviction order: If any item is expired, evict an expired item first. If no item is expired, evict the lowest-priority item. If priorities tie, evict the least-recently-used item. Notes The data-structure design needs indexes for expiration, priority, and recency. A practical answer uses a min-heap by expiration for expired candidates, a min-heap by (priority, last_access_time) for normal eviction, and lazy deletion to handle stale heap entries. get(key) must update recency if the existing class does not already do it. If get is truly black-box and cannot be changed, clarify where last-access time is maintained. Lazy deletion needs a version or pointer identity check; otherwise an old heap entry can evict a key after set has updated its priority or expiration. Define how to break ties among multiple expired items: earliest expiration is the natural choice unless the interviewer specifies otherwise. Preparation Implement evictItem() using store[key] -> item/version, expiry_heap, and priority_lru_heap; write a helper that pops stale heap entries until the top matches the current store. Drill the cache patterns behind the prompt: LRU for recency tie-breaks and LFU-style bucket thinking for ordered eviction criteria. Test expired-first behavior, priority ties, get recency updates, set updates that leave stale heap entries behind, empty cache, and identical timestamps.