import { CacheOptions, LruCache } from "./LruCache";
export type PromiseCacheOptions<V> = CacheOptions<Promise<V>> & {
    expireRejectedPromiseValues?: boolean;
    rejectedPromiseValueTtl?: number;
};
export declare class PromiseLruCache<K, V> extends LruCache<K, Promise<V>> {
    protected expireRejectedPromiseValues: boolean;
    protected rejectedPromiseValueTtl: number;
    constructor(options: PromiseCacheOptions<V>);
    set(key: K, value: Promise<V>, ttl?: number): void;
}