Java为什么我看不到我的令牌（JLabel）？

Question

这是我在Java中的小小垄断的代码。 当我使用新的Monopoly（）运行我的测试程序时;正如你所看到的，我在垄断，游戏中的圆形游戏中创造了测试，棋盘和游戏的垄断。我想将我的令牌添加到董事会。但是，我看不到令牌。我找不到问题任何人都可以帮助我吗？ （我甚至尝试过调试）

import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JPanel;

public class Board extends JPanel {
    private ImageIcon image;
    private JLabel label;

    public Board() {
        image = new ImageIcon("board.jpg");
        setLayout(null);
        label = new JLabel(new ImageIcon("board.jpg"));
        label.setSize(700, 700);
        add(label);
    }
}

public class Game {

    Player p1;
    Player p2;

    public Game(Board b) {
        p1 = new Player("Onurcan", 1);
        p2 = new Player("Baturay", 2);
        Round r = new Round(p1, b);
    }

    public Player getP1() {
        return p1;
    }

    public Player getP2() {
        return p2;
    }
}

public class Monopoly {

    public Monopoly() {
        JFrame frame = new JFrame("Monopoly");
        Board b = new Board();
        Game g = new Game(b);
        frame.setSize(1378, 900);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(b);
        frame.setVisible(true);
    }
}

public class Round {

    private static final int unitChange = 50;
    int posx1 = 650;
    int posy1 = 650;

    public Round(Player p, Board b) {
        Dice d = new Dice();
        p.setPosition((p.getPosition() + d.getDice()));
        if (p.getPosition() >= 40) {
            p.setPosition(p.getPosition() - 40);
        }
        changePosition(p, d, b);
    }

    public void changePosition(Player p, Dice d, Board b) {
        p.getToken().setSize(25,25);
        p.getToken().setLocation(posx1, posy1);
        b.add(p.getToken());    
    }
    public class Player {
    String pname;
    int balance;
    int pnumber;
    int position;
    JPanel token;

    public Player(String name, int pnumber) {
        pname = name;
        balance = 1500;
        position = 0;
        token = new Token(pnumber);
    }

    public JPanel getToken() {
        return token;
    }

    public int getBalance() {
        return balance;
    }

    public void setBalance(int balance) {
        this.balance = balance;
    }

    public int getPosition() {
        return position;
    }

    public void setPosition(int position) {
        this.position = position;
    }    
}