    /**
     *  Returns a non-terminating observable sequence, which can be used to denote an infinite duration (e.g. when using reactive joins).
     * @returns {Observable} An observable sequence whose observers will never get called.
     */
    var observableNever = Observable.never = function () {
        return new AnonymousObservable(function () {
            return disposableEmpty;
        });
    };
