Skeleton of Tictactoe Game Guided by TDD Using object oriented design

Board.java

public class Board {

    private final int BOUNDARY;
    private final Square boardLayout[][];

    public Board(int boundary) {
        this.BOUNDARY = boundary;
        boardLayout = new Square[BOUNDARY][BOUNDARY];
    }

    public boolean hasEmptyPosition() {
    }


    public boolean hasWon(Player player) {
        return isVerticallyFilled(player) || isHorizontallyFilled(player);
    }

    private boolean isHorizontallyFilled(Player player) {
    }

    private boolean isVerticallyFilled(Player player) {
    }

    public void placeMarker(Player player, Position position) {
        if(isLegalMove(getSquare(position))) {
            player.play(getSquare(position));
        }
    }

    private Square getSquare(Position position) {
    }

    private boolean isLegalMove(Square square) {
    }
}

Game.java

public class Game {
    private static final int BOUNDARY = 3;
    private Board board;
    private Queue<Player> players;

    public Game() {
        board = new Board();
        players = new LinkedList<>();

        addPlayers();

    }

    private void addPlayers() {
        players.add(new Player("X"));
        players.add(new Player("O"));
    }


    private void startGame() throws IOException {
     do {
         Player currentPlayer = players.remove();
         System.out.println("Enter position for Player "+currentPlayer.toString());

         java.io.BufferedReader in = new BufferedReader(new InputStreamReader(System.in));

         board.placeMarker(currentPlayer,new Position(Integer.parseInt(in.readLine()),Integer.parseInt(in.readLine())));
         players.add(currentPlayer);
         System.out.println(board.toString());
         if(board.hasWon(currentPlayer)){
             break;
         }
     }while (board.hasEmptyPosition());
    }




    public static void main(String[] args) {
        Game game= new Game();
        game.startGame();
      
    }
}

Player.java

public class Player {

    private final String type;

    Player(String type) {
        this.type = type;
    }

    public void play(Square square) {
        square.setPlayer(this);
    }
}

Square.java

public class Square {

    private final Position position;

    private Player player;

    public Square(Position position) {
        this.position = position;
    }

    public void setPlayer(Player player) {
        this.player = player;
    }

    public boolean isEmpty() {
        return player == null;
    }
}