NS_NOTREACHED("null node passed to GetTag()"); return atom;
NS_NOTREACHED("bad node passed to GetTag()"); return nsnull;
nsCOMPtr<nsIAtom> GetTag(nsIDOMNode *aNode){  nsCOMPtr<nsIAtom> atom;    if (!aNode)   {    NS_NOTREACHED("null node passed to GetTag()");    return atom;  }    nsCOMPtr<nsIContent> content = do_QueryInterface(aNode);  if (content)    content->GetTag(getter_AddRefs(atom));  return atom;}