A content management system requires a high-speed cache for key–value pairs, where each value has an associated rank indicating its priority or importance. Because the primary data source is slow, it's important to keep frequently accessed or high-ranked items readily available in the cache. When the cache is full, it should evict the entry with the lowest rank. If several entries share this minimum rank, any one of them can be removed.

You are given the following interfaces and class definitions: