subjectReader = $subjectReader; } /** * @inheritdoc */ public function build(array $buildSubject): array { $paymentDO = $this->subjectReader->readPayment($buildSubject); $payment = $paymentDO->getPayment(); $order = $paymentDO->getOrder(); $data = []; if ($payment instanceof Payment && $order instanceof Order) { $data = [ 'transactionRequest' => [ 'shipping' => [ 'amount' => $order->getBaseShippingAmount() ] ] ]; } return $data; } }