def METHOD_NAME():
    """
    test one time step with no uncertainty on the spill
    checks there is non-zero motion.
    also checks the motion is same for all LEs
    """
    pSpill = sample_sc_release(num_le, start_pos, rel_time,
                               windage_range=(0.03, 0.03))
    ice_mover = IceWindMover(ice_file, topology_file)
    delta = _certain_loop(pSpill, ice_mover)
    # _assert_move(delta)  # should get a new example that has some movement...
    # assert np.all(delta[:, 0] == delta[0, 0])  # lat move matches for all LEs
    # assert np.all(delta[:, 1] == delta[0, 1])  # long move matches for all LEs
    # in this case ice coverage is > 80% so no wind
    assert np.all(delta[:, 0] == 0)
    # in this case ice coverage is > 80% so no wind
    assert np.all(delta[:, 1] == 0)
    # 'z' is zeros
    assert np.all(delta[:, 2] == 0)