@reactivex/rxjs/src/add/observable/forkJoin.ts

Reactive Extensions for modern JavaScript

import {Observable} from '../../Observable';
import {forkJoin as staticForkJoin} from '../../observable/forkJoin';

Observable.forkJoin = staticForkJoin;

declare module '../../Observable' {
  namespace Observable {
    export let forkJoin: typeof staticForkJoin;
  }
}