import { Observable } from '../Observable';
/**
 * Returns an Observable that emits the same values as the source observable with the exception of an `error`.
 * An `error` will cause the emission of the Throwable that cause the error to the Observable returned from
 * notificationHandler. If that Observable calls onComplete or `error` then retry will call `complete` or `error`
 * on the child subscription. Otherwise, this Observable will resubscribe to the source observable, on a particular
 * Scheduler.
 *
 * <img src="./img/retryWhen.png" width="100%">
 *
 * @param {notificationHandler} receives an Observable of notifications with which a user can `complete` or `error`,
 * aborting the retry.
 * @param {scheduler} the Scheduler on which to subscribe to the source Observable.
 * @returns {Observable} the source Observable modified with retry logic.
 */
export declare function retryWhen<T>(notifier: (errors: Observable<any>) => Observable<any>): Observable<T>;