export declare class Backoff {
    private readonly attempts;
    private readonly min;
    private readonly max;
    private readonly scalar;
    private started;
    private done;
    private timeoutHandle;
    constructor(attempts: number, min: number, max: number, scalar: number);
    start(fn: () => Promise<void>): Promise<void>;
    cancel(): void;
    private backoff;
}