In-Memory Database — Levels 1–4 (TTL + Backup/Restore)

Requirements Build an in-memory database whose top-level keys each map to several string field/value pairs. Level 1 — basic operations Provide these operations: Level 2 — listing Add the following operations: scan must return every field belonging to key, ordered lexicographically by field name. scan_by_prefix uses the same output format and ordering, but includes only fields whose names begin with prefix. Level 3 — timestamps and TTL Create timestamp-aware versions of every…