PayPal\Api\Payer::addFundingInstrument PHP 메소드

    public function addFundingInstrument($fundingInstrument)
    {
        if (!$this->getFundingInstruments()) {
            return $this->setFundingInstruments(array($fundingInstrument));
        } else {
            return $this->setFundingInstruments(array_merge($this->getFundingInstruments(), array($fundingInstrument)));
        }
    }