declare class LRUCache { private readonly max; private readonly unusedTimeout?; private readonly checkoutInterval?; private readonly cacheMap; private readonly isAutoClear; private firstFrame; private lastFrame; private interval; constructor(max?: number, unusedTimeout?: number | undefined, checkoutInterval?: number | undefined); get(key: K): T | null; set(key: K, entry: T): void; delete(key: K): boolean; clear(): void; private setInterval; private clearUnused; } export = LRUCache;