public Position move(TileGeometry position, int sizeMove) {
		if (position == null || position == TileGeometry.CENTER) {
			throw new IllegalArgumentException();
		}
		switch (position) {
		case NORTH:
			return new Position(xmin, ymin - sizeMove, xmax, ymax - sizeMove);
		case SOUTH:
			return new Position(xmin, ymin + sizeMove, xmax, ymax + sizeMove);
		case WEST:
			return new Position(xmin - sizeMove, ymin, xmax - sizeMove, ymax);
		case EAST:
			return new Position(xmin + sizeMove, ymin, xmax + sizeMove, ymax);
		default:
			throw new IllegalStateException();
		}
	}