nsresult result = NS_OK;
if (mRoot) { return NS_OK; }
nsHTMLFragmentContentSink::WillBuildModel(void){  nsresult result = NS_OK;  if (nsnull == mRoot) {    nsIDOMDocumentFragment* frag;    result = NS_NewDocumentFragment(&frag, nsnull);    if (NS_SUCCEEDED(result)) {      result = frag->QueryInterface(NS_GET_IID(nsIContent), (void**)&mRoot);      NS_RELEASE(frag);    }  }  return result;}