export declare class CacheService {
    private cache;
    private hitCount;
    private missCount;
    constructor(defaultTtl?: number);
    getOrSet<T>(key: string, fetchFn: () => Promise<T>, ttl?: number): Promise<T>;
    get<T>(key: string): T | undefined;
    set<T>(key: string, value: T, ttl?: number): boolean;
    del(key: string): number;
    flush(): void;
    getStats(): any;
}