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