import * as anchor from "@coral-xyz/anchor";
import { BlockhashWithExpiryBlockHeight } from "@solana/web3.js";
export declare class BlockhashWithCache {
    readonly provider: anchor.Provider;
    readonly ttl: number;
    private cachedBlockhash;
    private fetchPromise;
    constructor(provider: anchor.Provider, ttl?: number);
    get(): Promise<BlockhashWithExpiryBlockHeight>;
    clear(): void;
}