/**
* Appends this element to its parent if necessary.
*
* @internal
*/
protected function _ensureAppended()
{
if (!$this->_appended) {
$parentDom = $this->_parentElement->getDom();
if (!$parentDom->ownerDocument->isSameNode($this->_element->ownerDocument)) {
$this->_element = $parentDom->ownerDocument->importNode($this->_element, true);
}
$parentDom->appendChild($this->_element);
$this->_appended = true;
$this->_parentElement->_ensureAppended();
}
}