protected static function loadObFees($obFees, $obFeeRefs)
    {
        $opt = [];

        if (!empty($obFees)) {
            $po = new PricingOptionGroup(PricingOptionKey::OPTION_OB_FEES);

            $po->penDisInformation = new PenDisInformation(
                PenDisInformation::QUAL_OB_FEES,
                $obFees
            );

            if (!empty($obFeeRefs)) {
                $po->paxSegTstReference = new PaxSegTstReference($obFeeRefs);
            }

            $opt[] = $po;
        }

        return $opt;
    }