private void renderBoard(Board board, PrintStream out) {
        for (Hex h : Board.allHexes()) {
            Resource r = board.resourceAt(h);
            if (r != null)
                out.println(h + " " + r.chr() + " " + board.numberAt(h));
        }

        for (Node n : Board.allNodes()) {
            Harbor harbor = board.harborAt(n);
            if (harbor != null && harbor.resource != null)
                out.println(n + " " + harbor.resource.chr());
        }
        for (Node n : Board.allNodes()) {
            Harbor harbor = board.harborAt(n);
            if (harbor != null && harbor.resource == null)
                out.println(n);
        }
    }