@reactivex/rxjs/src/add/operator/takeUntil.ts

Reactive Extensions for modern JavaScript

import {Observable} from '../../Observable';
import {takeUntil, TakeUntilSignature} from '../../operator/takeUntil';

Observable.prototype.takeUntil = takeUntil;

declare module '../../Observable' {
  interface Observable<T> {
    takeUntil: TakeUntilSignature<T>;
  }
}