src/Payum/Paypal/ProCheckout/Nvp/Api.php
public function doCredit(array $fields)
    {
        $fields['TRXTYPE'] = self::TRXTYPE_CREDIT;
        $this->addAuthorizeFields($fields);

        $result = $this->doRequest($fields);
        $result['TRXTYPE'] = self::TRXTYPE_CREDIT;

        return $result;
    }
public function doCredit(array $fields)
    {
        $fields['TRXTYPE'] = self::TRXTYPE_CREDIT;
        $this->addAuthorizeFields($fields);

        $result = $this->doRequest($fields);
        $result['TRXTYPE'] = self::TRXTYPE_CREDIT;

        return $result;
    }
@param array $fields

@return array