src/Utilities.php
public static function appendChild(stdClass $object, $propertyName, DOMNode $node)
    {
        if (isset($object->{$propertyName})) {
            $node->appendChild($node->ownerDocument->createElement($propertyName, $object->{$propertyName}));
        }
    }
public static function appendChild(stdClass $object, $propertyName, DOMNode $node)
    {
        if (isset($object->{$propertyName})) {
            $node->appendChild($node->ownerDocument->createElement($propertyName, $object->{$propertyName}));
        }
    }
Conditionally adds a child node to $node. The value comes from the specified $object
and will only be added if the $propertyName has a value.

@param stdClass $object The object to get values from
@param string $propertyName The property name to access
@param DOMNode $node The node to add the child to

@deprecated Use NodeInterface on entities instead