Implement a Cache Snapshot Printer

Implement an LRU-style cache and a snapshot-printing feature. The cache stores key-value pairs and has a fixed capacity. It should support normal cache operations such as inserting/updating a key and reading a key. When the capacity is exceeded, the least recently used entry should be evicted. Add a function `snapshot(cache)` that returns a printable representation of the current cache contents in recency order. Then extend the snapshot logic to support compressed output. Given a compression utility, group entries that have the same value. For example, if the cache snapshot contains: ```text A: 2 B: 2 ``` the compressed snapshot can be represented as: ```text 2 [A, B] ``` Clarify and implement how ordering should be preserved in the compressed output, especially when multiple values appear in the cache.