notifyComplete() {
        runtime_1.assert(!this.closed, 'stream is closed');
        this._closed = true;
        this.pushIt({ value: null, done: true });
        this._lis.cmp.forEach(l => l());
        this._lis.nxt.forEach(l => l(undefined, undefined, true));
        this.clearLis();
    }
Closes the stream successfully. Throws if stream is closed.

Triggers onNext and onComplete callbacks.