public Collection<Collection<T>> cellsFor(
IntersectionTestObject object) {
assert(gridBounds.contains(object));
AxisAlignedBoundingBoxXZ objectAABB = object.getAxisAlignedBoundingBoxXZ();
int minCellX = cellXForCoord(objectAABB.minX, objectAABB.minZ);
int minCellZ = cellZForCoord(objectAABB.minX, objectAABB.minZ);
int maxCellX = cellXForCoord(objectAABB.maxX, objectAABB.maxZ);
int maxCellZ = cellZForCoord(objectAABB.maxX, objectAABB.maxZ);