не понимаю в чем ошибка
package com.javarush.games.minesweeper;
import com.javarush.engine.cell.Color;
import com.javarush.engine.cell.Game;
import java.util.ArrayList;
import java.util.List;
public class MinesweeperGame extends Game {
private static final int SIDE = 21;
private GameObject[][] gameField = new GameObject[SIDE][SIDE];
private int countMinesOnField;
private static final String MINE = "\uD83D\uDCA3";
private static final String FLAG = "\uD83D\uDEA9";
private int countFlags;
private void openTile(int x, int y){
if (gameField[y][x].isMine) {
setCellValue(x, y, MINE);
setCellColor(x, y, Color.RED);
} else{
setCellNumber(x, y, gameField[y][x].countMineNeighbors);
setCellColor(x, y, Color.VIOLET);
gameField[y][x].isOpen = true;
if (gameField[y][x].countMineNeighbors == 0) {
setCellValue(x, y, "");
for (GameObject gameObject : getNeighbors(gameField[y][x])) {
if (!gameObject.isOpen) {
openTile(gameObject.x, gameObject.y);
}
gameField[y][x].isOpen = true;
}
}
}
gameField[y][x].isOpen = true;
}
private void markTile(int x, int y){
if (gameField[y][x].isOpen && gameField[y][x].isFlag){
if (gameField[y][x].isFlag) {
gameField[y][x].isFlag = false;
countFlags = countFlags +1;
setCellValue(x, y, "");
setCellColor(x, y, Color.ORANGE);
}else if (gameField[y][x].isOpen == false && countFlags > 0) {
setCellValue(x, y, FLAG);
setCellColor(x, y, Color.YELLOW);
gameField[y][x].isFlag = true;
countFlags = countFlags-1;
}
}
}
public void onMouseLeftClick(int y, int x){
openTile(y, x);
}
@Override
public void onMouseRightClick(int y, int x){
markTile(y,x);
}
private void countMineNeighbors(){
List<GameObject> gamelist;
for (int y = 0; y < SIDE; y++) {
for (int x = 0; x < SIDE; x++) {
if (!gameField[y][x].isMine){
gamelist = getNeighbors(gameField[y][x]);
for (int i = 0; i < gamelist.size(); i++) {
if (gamelist.get(i).isMine) {
gameField[y][x].countMineNeighbors++;
}
}
}
}
}
}
public void initialize() {
setScreenSize(SIDE, SIDE);
createGame();
}
private void createGame() {
for (int y = 0; y < SIDE; y++) {
for (int x = 0; x < SIDE; x++) {
boolean mine = getRandomNumber(10) < 1;
if (mine) {
countMinesOnField++;
}
gameField[y][x] = new GameObject(x, y, mine);
setCellColor(x, y, Color.BLUE);
}
}
countMineNeighbors();
countFlags = countMinesOnField;
}
private List<GameObject> getNeighbors(GameObject gameObject) {
List<GameObject> result = new ArrayList<>();
for (int y = gameObject.y - 1; y <= gameObject.y + 1; y++) {
for (int x = gameObject.x - 1; x <= gameObject.x + 1; x++) {
if (y < 0 || y >= SIDE) {
continue;
}
if (x < 0 || x >= SIDE) {
continue;
}
if (gameField[y][x] == gameObject) {
continue;
}
result.add(gameField[y][x]);
}
}
return result;
}
}