code: public function toNode(DOMDocument $document = null)
      {
          if (null === $document) {
              $document = new DOMDocument();
          }
          $node = $document->createElement('CODAmount');
          if ($this->CurrencyCode) {
              $node->appendChild($document->createElement('CurrencyCode', $this->CurrencyCode));
          }
          if ($this->MonetaryValue) {
              $node->appendChild($document->createElement('MonetaryValue', $this->MonetaryValue));
          }
          return $node;
      }
docs: @param null|DOMDocument $document
  
  @return DOMElement