def METHOD_NAME():
    e = XrfElement("Fe")
    # test at different energies
    for eng in range(10, 20):
        cs1 = np.array([v for k, v in e.cs(eng).all])  # unit in cm2/g
        cs2 = np.array([v for k, v in e.csb(eng).all])  # unit in barns/atom
        cs1 /= cs1[0]
        cs2 /= cs2[0]
        # ratio should be the same no matter which unit is used
        assert_array_almost_equal(cs1, cs2, decimal=10)