Method onError

packages/engine.io/lib/socket.ts:201–204

* Called upon transport error. * * @param {Error} err - error object * @private

(err: Error)

   * @private
   */
  private onError(err: Error) {
    debug("transport error");
    this.onClose("transport error", err);
  }

  /**
   * Pings client every `this.pingInterval` and expects response