import { GenericError } from './error';
export declare const base64: (stringValue: string) => string;
export declare function retry<T>(target: any, operation: (retryCount: number) => Promise<T>, retryShouldStop: () => boolean, options?: {
    delay?: (retryCount: number) => number;
    onFailAttempt?: (err: GenericError) => void;
}): Promise<[err?: GenericError, result?: T]>;