getter_AddRefs(modelNode),
getter_AddRefs(model),
nsXFormsValueElement::GetValue(nsAString &aValue){  nsCOMPtr<nsIDOMNode> modelNode;  nsCOMPtr<nsIDOMXPathResult> result;  nsXFormsUtils::EvaluateNodeBinding(mElement,                                     nsXFormsUtils::ELEMENT_WITH_MODEL_ATTR,                                     NS_LITERAL_STRING("ref"),                                     EmptyString(),                                     nsIDOMXPathResult::FIRST_ORDERED_NODE_TYPE,                                     getter_AddRefs(modelNode),                                     getter_AddRefs(result));  if (result) {    nsCOMPtr<nsIDOMNode> singleNode;    result->GetSingleNodeValue(getter_AddRefs(singleNode));    if (singleNode) {      nsString value;      nsXFormsUtils::GetNodeValue(singleNode, value);      aValue.Assign(value);      return NS_OK;    }  }  nsCOMPtr<nsIDOM3Node> node3 = do_QueryInterface(mElement);  NS_ASSERTION(node3, "dom elements must support dom3");  return node3->GetTextContent(aValue);}