return NS_ERROR_ALREADY_INITIALIZED;
NS_PRECONDITION(aContent != nsnull, "no content"); if (! aContent) return NS_ERROR_NULL_POINTER;  nsCOMPtr<nsIDocument> doc; aContent->GetDocument(*getter_AddRefs(doc)); NS_ASSERTION(doc != nsnull, "element not in the document"); if (! doc) return NS_ERROR_FAILURE;  nsCOMPtr<nsIBindingManager> mgr; doc->GetBindingManager(getter_AddRefs(mgr)); if (! mgr) return NS_ERROR_FAILURE;    nsCOMPtr<nsIDOMNodeList> nodes; mgr->GetXBLChildNodesFor(aContent, getter_AddRefs(nodes));  PRUint32 length; if (nodes) nodes->GetLength(&length); else aContent->ChildCount(NS_REINTERPRET_CAST(PRInt32&, length));  aFirst->mContent = aContent; aLast->mContent  = aContent; aFirst->mIndex   = 0; aLast->mIndex    = length; aFirst->mNodes   = nodes; aLast->mNodes    = nodes;  return NS_OK;
GeneratedContentIterator::Init(nsIContent* aRoot){  return NS_ERROR_ALREADY_INITIALIZED;}