void setSize(int width, int height) {
		if (this.width != width) {
			this.width = width;
			walls.remove(xAxisWall);
			walls.add(xAxisWall = new Wall(1, 0, width, Display.HORIZONTAL));
		}

		if (this.height != height) {
			this.height = height;
			walls.remove(yAxisWall);
			walls.add(yAxisWall = new Wall(0, 1, height, Display.VERTICAL));
		}
	}