return cN;
return deepFirstChild;
nsCOMPtr<nsIContent> nsContentIterator::GetDeepFirstChild(nsCOMPtr<nsIContent> aRoot){  if (!aRoot)     return aRoot;      nsCOMPtr<nsIContent> cN = aRoot;  nsCOMPtr<nsIContent> cChild;  cN->ChildAt(0,*getter_AddRefs(cChild));  while ( cChild )  {    cN = cChild;    cN->ChildAt(0,*getter_AddRefs(cChild));  }  return cN;}