@omneedia/socketcluster/sample/node_modules/rxjs/src/add/observable/interval.ts

SocketCluster - A Highly parallelized WebSocket server cluster to make the most of multi-core machines/instances.

import { Observable } from '../../Observable';
import { interval as staticInterval } from '../../observable/interval';

Observable.interval = staticInterval;

declare module '../../Observable' {
  namespace Observable {
    export let interval: typeof staticInterval;
  }
}