Не проходит последний пункт

package com.javarush.games.spaceinvaders; import com.javarush.engine.cell.*; import com.javarush.games.spaceinvaders.gameobjects.*; import java.util.ArrayList; import java.util.List; public class SpaceInvadersGame extends Game { public static final int WIDTH = 64; public static final int HEIGHT = 64; private List<Star> stars; private void createStars(){ stars = new ArrayList<>(); for (int i=0; i < 8; i++) { stars.add(new Star(getRandomNumber(WIDTH-1), getRandomNumber(HEIGHT-1))); } } @Override public void initialize(){ setScreenSize(WIDTH, HEIGHT); createGame(); } private void createGame(){ createStars(); drawScene(); } private void drawScene(){ drawField(); } private void drawField() { for (int x = 0; x < WIDTH; x++) { for (int y = 0; y < HEIGHT; y++) { setCellValueEx(x, y, Color.BLACK, ""); } } for (int i = 0; i < stars.size(); i++) { stars.get(i).draw(this); } } } package com.javarush.games.spaceinvaders.gameobjects; import com.javarush.engine.cell.*; public class Star extends GameObject { private static final String STAR_SIGN = "\u2605"; public Star(double x, double y) { super(x, y); } public void draw(Game game) { game.setCellValueEx((int) x, (int) y, Color.NONE, STAR_SIGN, Color.WHITE, 100); } } package com.javarush.games.spaceinvaders.gameobjects; public class GameObject { public double x; public double y; public GameObject ( double x,double y) { this.x = x; this.y = y; } }