import { Observable, UnaryFunction } from 'rxjs';
import { TestScheduler } from 'rxjs/testing';
export declare class SubscriptionLog {
    subscribedFrame: number;
    unsubscribedFrame: number;
    constructor(subscribedFrame: number, unsubscribedFrame?: number);
}
export declare type SubscriptionLoggedObservable<T> = Observable<T> & {
    subscriptions: SubscriptionLog[];
};
export declare function isSubscriptionLoggedObservable<T>(obj: any): obj is SubscriptionLoggedObservable<T>;
export declare function wrapLogSubscriptions<T>(scheduler: TestScheduler, source: Observable<T>): SubscriptionLoggedObservable<T>;
export declare type LogSubscriptionsOperatorFunction<T> = UnaryFunction<Observable<T>, SubscriptionLoggedObservable<T>>;
export declare function logSubscriptions<T>(scheduler: TestScheduler): LogSubscriptionsOperatorFunction<T>;