code: private static function propertyToXml($name, $value)
      {
          if (is_subclass_of($value, '\DTS\eBaySDK\Types\BaseType', false)) {
              return $value->toXml($name);
          } else {
              return sprintf('<%s>%s</%s>', $name, self::encodeValueXml($value), $name);
          }
      }
docs: Helper function to convert an property into XML
  
  @param string $name The property name.
  @param mixed $value The property value.
  
  @return string The XML.