private void createWalls()
    {
        for (int i = 140; i <= 200; i += Object.size) {
            for (int j = 100; j <= 160; j += Object.size) {                
                gameObjects.put(createCoordinateKey(new Coordination(j, i)), new Brick(j, i));
            }
        }
        
        for (int i = 140; i <= 200; i += Object.size) {
            for (int j = 320; j <= 380; j += Object.size) {                
                gameObjects.put(createCoordinateKey(new Coordination(j, i)), new Brick(j, i));
            }
        }
        
        for (int i = 360; i <= 420; i += Object.size) {
            for (int j = 100; j <= 160; j += Object.size) {                
                gameObjects.put(createCoordinateKey(new Coordination(j, i)), new Brick(j, i));
            }
        }
        
        for (int i = 360; i <= 420; i += Object.size) {
            for (int j = 320; j <= 380; j += Object.size) {                
                gameObjects.put(createCoordinateKey(new Coordination(j, i)), new Brick(j, i));
            }
        }
        
        //gameObjects.put(createCoordinateKey(new Coordination(100, 520)), new Brick(100, 520));
        
    }