import { Observable } from '../Observable';
import { Subscriber } from '../Subscriber';
/**
 * We need this JSDoc comment for affecting ESDoc.
 * @extends {Ignored}
 * @hide true
 */
export declare class NeverObservable<T> extends Observable<T> {
    /**
     * Creates an Observable that emits no items to the Observer.
     *
     * <span class="informal">An Observable that never emits anything.</span>
     *
     * <img src="./img/never.png" width="100%">
     *
     * This static operator is useful for creating a simple Observable that emits
     * neither values nor errors nor the completion notification. It can be used
     * for testing purposes or for composing with other Observables. Please note
     * that by never emitting a complete notification, this Observable keeps the
     * subscription from being disposed automatically. Subscriptions need to be
     * manually disposed.
     *
     * @example <caption>Emit the number 7, then never emit anything else (not even complete).</caption>
     * function info() {
     *   console.log('Will not be called');
     * }
     * var result = Rx.Observable.never().startWith(7);
     * result.subscribe(x => console.log(x), info, info);
     *
     * @see {@link create}
     * @see {@link empty}
     * @see {@link of}
     * @see {@link throw}
     *
     * @return {Observable} A "never" Observable: never emits anything.
     * @static true
     * @name never
     * @owner Observable
     */
    static create<T>(): NeverObservable<T>;
    constructor();
    protected _subscribe(subscriber: Subscriber<T>): void;
}
