import { OrderSubscriber } from './OrderSubscriber';
export declare class PollingSubscription {
    private orderSubscriber;
    private frequency;
    intervalId?: ReturnType<typeof setTimeout>;
    constructor({ orderSubscriber, frequency, }: {
        orderSubscriber: OrderSubscriber;
        frequency: number;
    });
    subscribe(): Promise<void>;
    unsubscribe(): Promise<void>;
}