rv = parent->AppendChildTo(element, aNotify);
rv = parent->AppendChildTo(element, aNotify, PR_FALSE);
nsXULContentBuilder::EnsureElementHasGenericChild(nsIContent* parent,                                                  PRInt32 nameSpaceID,                                                  nsIAtom* tag,                                                  PRBool aNotify,                                                  nsIContent** result){    nsresult rv;    rv = nsXULContentUtils::FindChildByTag(parent, nameSpaceID, tag, result);    if (NS_FAILED(rv)) return rv;    if (rv == NS_RDF_NO_VALUE) {        // we need to construct a new child element.        nsCOMPtr<nsIContent> element;        rv = CreateElement(nameSpaceID, tag, getter_AddRefs(element));        if (NS_FAILED(rv)) return rv;        // XXX Note that the notification ensures we won't batch insertions! This could be bad! - Dave        rv = parent->AppendChildTo(element, aNotify);        if (NS_FAILED(rv)) return rv;        *result = element;        NS_ADDREF(*result);        return NS_RDF_ELEMENT_GOT_CREATED;    }    else {        return NS_RDF_ELEMENT_WAS_THERE;    }}