def test_second_nearest_neighbors_distance(self):
lattice = HexagonalLattice([8, 8])
nn = lattice.second_nearest_neighbors(LatticeSite([0, 0]))
nn = [lattice.spatial_coordinates(point) for point in nn]
norms = [sum(a * a for a in point) for point in nn]
assert min(norms) + .0000001 > max(norms)
