contains method
Returns true if the given AABB is fully contained in this AABB.
Implementation
bool contains(AABB aabb) {
final l1 = lowerBound;
final u1 = upperBound;
final l2 = aabb.lowerBound;
final u2 = aabb.upperBound;
// l2 u2
// |---------|
// |---------------|
// l1 u1
return (
(l1.x <= l2.x && u1.x >= u2.x) &&
(l1.y <= l2.y && u1.y >= u2.y) &&
(l1.z <= l2.z && u1.z >= u2.z)
);
}