How to use the @nestjsx/util.isUndefined function in @nestjsx/util

      .filter((d) => !isUndefined(d));

            .filter((d) => !util_1.isUndefined(d));
        if (!util_1.hasLength(bulk)) {

private checkQueryObjectParam(
    cond: keyof RequestQueryBuilderOptions['paramNamesMap'],
    defaults: any,
  ): string {
    const param = this.paramNames[cond];
    if (isNil(this.queryObject[param]) && !isUndefined(defaults)) {
      this.queryObject[param] = defaults;
    }
    return param;
  }

      .filter((d) => !isUndefined(d));