uint[4] sides = [1, 2, 3, 4];
assert(sides.sideX == [sides.sideLeft, sides.sideRight]);
assert(sides.sideY == [sides.sideTop, sides.sideBottom]);
sides.sideX = 8;
assert(sides == [8, 8, 3, 4]);
sides.sideY = sides.sideBottom;
assert(sides == [8, 8, 4, 4]);