@reactivex/rxjs/dist/amd/src/add/operator/throttle.ts

Reactive Extensions for modern JavaScript

import {Observable} from '../../Observable';
import {throttle, ThrottleSignature} from '../../operator/throttle';

Observable.prototype.throttle = throttle;

declare module '../../Observable' {
  interface Observable<T> {
    throttle: ThrottleSignature<T>;
  }
}