public String saveTree(Tree t, String dirLocation, int boardSize, int numberOfPlayers) throws FileNotFoundException, IOException{
        if(currentTree!=null && !currentTree.getNodesOfLevel(1).isEmpty()){
            String fn = getFileName(dirLocation, boardSize, numberOfPlayers);
            FileOutputStream str = new FileOutputStream(fn);
            ObjectOutputStream ostr = new ObjectOutputStream(str);
            ostr.writeObject(currentTree);
            ostr.close();
            str.close();
            return fn;
        } else{
            return null;
        }
    }