How to use the @firebase/webchannel-wrapper.ErrorCode.TIMEOUT function in @firebase/webchannel-wrapper

xhr.listenOnce(EventType.COMPLETE, () => {
        try {
          switch (xhr.getLastErrorCode()) {
            case ErrorCode.NO_ERROR:
              const json = xhr.getResponseJson() as Resp;
              log.debug(LOG_TAG, 'XHR received:', JSON.stringify(json));
              resolve(json);
              break;
            case ErrorCode.TIMEOUT:
              log.debug(LOG_TAG, 'RPC "' + rpcName + '" timed out');
              reject(
                new FirestoreError(Code.DEADLINE_EXCEEDED, 'Request time out')
              );
              break;
            case ErrorCode.HTTP_ERROR:
              const status = xhr.getStatus();
              log.debug(
                LOG_TAG,
                'RPC "' + rpcName + '" failed with status:',
                status,
                'response text:',
                xhr.getResponseText()
              );
              if (status > 0) {
                const responseError = (xhr.getResponseJson() as WebChannelError)