/**
  * save the invoice instructions from paypal
  *
  * @param string $orderNumber
  * @param array $payment
  */
 private function saveInvoiceInstructions($orderNumber, array $payment)
 {
     $paymentInstructionProvider = new PaymentInstructionProvider($this->paypalBootstrap->get('db'));
     $paymentInstructionProvider->saveInstructionByOrderNumber($orderNumber, $payment['payment_instruction']);
 }