code: public function toNode(DOMDocument $document = null)
      {
          if (null === $document) {
              $document = new DOMDocument();
          }
  
          $packageNode = $document->createElement('Package');
  
          if ($this->getDescription()) {
              $packageNode->appendChild($document->createElement('Description', $this->getDescription()));
          }
          $packageNode->appendChild($this->getPackagingType()->toNode($document));
          $packageNode->appendChild($this->getPackageWeight()->toNode($document));
  
  
          if (null !== $this->getDimensions()) {
              $packageNode->appendChild($this->getDimensions()->toNode($document));
          }
  
          if ($this->isLargePackage()) {
              $packageNode->appendChild($document->createElement('LargePackageIndicator'));
          }
  
          if ($this->getAdditionalHandling()) {
              $packageNode->appendChild($document->createElement('AdditionalHandling'));
          }
  
          if ($this->getPackageServiceOptions()) {
              $packageNode->appendChild($this->getPackageServiceOptions()->toNode($document));
          }
  
          if ($this->getReferenceNumber()
              && !is_null($this->getReferenceNumber()->getCode())
              && !is_null($this->getReferenceNumber()->getValue())
          ) {
              $packageNode->appendChild($this->getReferenceNumber()->toNode($document));
          }
          
          if ($this->getReferenceNumber2()
              && !is_null($this->getReferenceNumber2()->getCode())
              && !is_null($this->getReferenceNumber2()->getValue())
          ) {
              $packageNode->appendChild($this->getReferenceNumber2()->toNode($document));
          }
  
          return $packageNode;
      }
docs: @param null|DOMDocument $document
  
  @return DOMElement