import type { DnsClient, IEnr } from "@waku/interfaces";
export declare class DnsNodeDiscovery {
    private readonly dns;
    private readonly _DNSTreeCache;
    static dnsOverHttp(dnsClient?: DnsClient): Promise<DnsNodeDiscovery>;
    constructor(dns: DnsClient);
    /**
     * Retrieve the next peers from the passed [[enrTreeUrls]],
     */
    getNextPeer(enrTreeUrls: string[]): AsyncGenerator<IEnr>;
    /**
     * Runs a recursive, randomized descent of the DNS tree to retrieve a single
     * ENR record as an ENR. Returns null if parsing or DNS resolution fails.
     */
    private _search;
    /**
     * Retrieves the TXT record stored at a location from either
     * this DNS tree cache or via DNS query.
     *
     * @throws if the TXT Record contains non-UTF-8 values.
     */
    private _getTXTRecord;
}