/**
 * Utility class that can encapsulate a DidAuthResponseToken
 * and keep track of its expiry time according to the local
 * time of the client. This is needed in case the local
 * time of the client can diverge from the server time
 */
export declare class LocalExpiringDidAuthResponseToken {
    private readonly _didAuthResponseToken;
    private readonly _expireAt;
    static readonly DEFAULT_EXPIRY_BUFFER: number;
    private constructor();
    isExpiredAt(time: number): boolean;
    toString(): string;
    /**
     * @param tokenRequestTime unix timestamp in milliseconds
     * @param token the did auth response token
     * @param expiryBuffer milliseconds
     */
    static initialize(tokenRequestTime: number, token: string, expiryBuffer?: number): LocalExpiringDidAuthResponseToken;
    private static calculateExpireAt;
}