export declare function exponentialBackoffDelay(currentFailureCount: number, minDelay: number, maxDelay: number, maxFailureCount: number): number;
export declare function backoff<T>(callback: () => Promise<T>, opts?: {
    onError?: (e: any, failuresCount: number) => void;
    minDelay?: number;
    maxDelay?: number;
    maxFailureCount?: number;
}): Promise<T>;