@omneedia/socketcluster/sample/node_modules/rxjs/src/add/operator/concat.ts

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

import { Observable } from '../../Observable';
import { concat } from '../../operator/concat';

Observable.prototype.concat = concat;

declare module '../../Observable' {
  interface Observable<T> {
    concat: typeof concat;
  }
}