}
} else if (newChild instanceof CoreDocumentFragment) {
if (nextSibling == null) {
coreAppendChildren((CoreDocumentFragment)newChild);
} else {
nextSibling.coreInsertSiblingsBefore((CoreDocumentFragment)newChild);
}
} else {
throw newDOMException(DOMException.HIERARCHY_REQUEST_ERR);
}
return _oldChild;