private function mapPayoutCompletedTransactions($payoutCompletedTransactions)
 {
     $transactions = array();
     foreach ($payoutCompletedTransactions as $index => $payoutCompletedTransaction) {
         $transaction = new PayoutCompletedTransaction();
         if (isset($payoutCompletedTransaction->paymentTransactionId)) {
             $transaction->setPaymentTransactionId($payoutCompletedTransaction->paymentTransactionId);
         }
         if (isset($payoutCompletedTransaction->payoutAmount)) {
             $transaction->setPayoutAmount($payoutCompletedTransaction->payoutAmount);
         }
         if (isset($payoutCompletedTransaction->payoutType)) {
             $transaction->setPayoutType($payoutCompletedTransaction->payoutType);
         }
         if (isset($payoutCompletedTransaction->subMerchantKey)) {
             $transaction->setSubMerchantKey($payoutCompletedTransaction->subMerchantKey);
         }
         if (isset($payoutCompletedTransaction->currency)) {
             $transaction->setCurrency($payoutCompletedTransaction->currency);
         }
         $transactions[$index] = $transaction;
     }
     return $transactions;
 }