result = NS_NewDocumentFragment(&frag, nsnull); if (NS_SUCCEEDED(result)) { result = frag->QueryInterface(NS_GET_IID(nsIContent), (void**)&mRoot); NS_RELEASE(frag); } } return result;
return CallQueryInterface(frag, &mRoot);
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;}