/**
 * @ignore
 */
export declare class KlevuFetchCache<T extends object, K extends object> {
    _cache: Map<number, string>;
    _timestamp: Map<number, number>;
    /**
     * checks if cache has value and returns it
     *
     * @param key
     * @param force For testing purposes
     * @returns undefined if not cached
     */
    check(key: T, force?: boolean): K | undefined;
    cache(key: T, data: K, timetocache?: number): void;
    private hash;
}