function ttlCache ttlCache<K,V,>(ttlMs: number,now?: () => number,): TtlCache<K, V> Create a TTL (Time-To-Live) cache. Entries expire after ttlMs milliseconds. Accepts an optional clock function for testing. Type Parameters K V Parameters ttlMs: number optional now: () => number = [Date.now] Return Type TtlCache<K, V>