import { HttpRequest, HttpResponse } from '@angular/common/http';
import { Cache } from './cache';
export declare abstract class HttpCache extends Cache {
    /**
     * Returns a cached response, if any, or null if not present.
     */
    abstract get(req: HttpRequest<any>): HttpResponse<any> | null;
    /**
     * Adds or updates the response in the cache.
     */
    abstract put(req: HttpRequest<any>, resp: HttpResponse<any>): void;
}