Can someone help me out with these? It did not give any xml class, this is the only thing it gives

luppearg(NaturaINumber n, int digit) 8. Complete the body of one return statement. it satisf ongestText so it satisfies its contract. For full credit, you must use recursion and only * Reports the text of the longest plain text node in the XMLTree t. @param t the XMLTree * @return the text of the longest plain text node in t * @requires [t has at least one plain text node] * @ensures longestText [the text of the longest plain text node in t) private static String longestText (XMLTree t) t