def test_cell_cell_connectivity():

    data, _ = three_faces_sheet()
    mono = Monolayer("test", extrude(data), bulk_spec())
    ccc = connectivity.cell_cell_connectivity(mono)
    expected = np.array([[0, 36, 36], [36, 0, 36], [36, 36, 0]])
    np.testing.assert_array_equal(ccc, expected)