Paypal支付获得发件人项目ID

How do I get the "sender item id" from a retrived PayoutItem

try {

            $output = \PayPal\Api\PayoutItem::get($payoutItemId, $this->apiContext);

        } catch (\Exception $e) {

            return $e->getMessage();
        }

// trasaction_id - works fine
            $transactionStatus = $output->getTransactionId();

            // trasaction_status - works fine
            $transactionId = $output->getTransactionStatus();

// ERROR
$senderItemId = $output->getSenderItemId();

Error:

Call to undefined method PayPal\Api\PayoutItemDetails::getSenderItemId()

upon inspection it looks like the PayoutItem class has the getSenderItemId() public function available - but the PayoutItemDetails class which is returned by the static get method on PayoutItem does not.

How can I get the senderItemId? :(

Payout item class - https://github.com/paypal/PayPal-PHP-SDK/blob/master/lib/PayPal/Api/PayoutItem.php

So turns out PayoutItemDetails class also returns a PayoutItem object.

So I can get the sender item id like so:

// WRONG
$senderItemId = $output->getSenderItemId();

// RIGHT
$senderItemId = $output->getPayoutItem()->getSenderItemId();