def METHOD_NAME(self):
    """
    Test :func:`colour.appearance.rlab.XYZ_to_RLAB` definition.
    Notes
    -----
    -   The test values have been generated from data of the following file
        by *Fairchild (2013)*:
        http://rit-mcsl.org/fairchild//files/AppModEx.xls
    """
    XYZ = np.array([19.01, 20.00, 21.78])
    XYZ_n = np.array([95.05, 100.00, 108.88])
    Y_n = 318.31
    sigma = 0.4347
    np.testing.assert_allclose(
        XYZ_to_RLAB(XYZ, XYZ_n, Y_n, sigma),
        np.array([49.67, 0.01, 270, 0, np.nan, 0, -0.01]),
        rtol=0.01,
        atol=0.01,
    )
    XYZ = np.array([57.06, 43.06, 31.96])
    Y_n = 31.83
    np.testing.assert_allclose(
        XYZ_to_RLAB(XYZ, XYZ_n, Y_n, sigma),
        np.array([69.33, 49.74, 21.3, 0.72, np.nan, 46.33, 18.09]),
        rtol=0.01,
        atol=0.01,
    )
    XYZ = np.array([3.53, 6.56, 2.14])
    XYZ_n = np.array([109.85, 100.00, 35.58])
    Y_n = 318.31
    np.testing.assert_allclose(
        XYZ_to_RLAB(XYZ, XYZ_n, Y_n, sigma),
        np.array([30.78, 41.02, 176.9, 1.33, np.nan, -40.96, 2.25]),
        rtol=0.01,
        atol=0.01,
    )
    XYZ = np.array([19.01, 20.00, 21.78])
    Y_n = 31.83
    np.testing.assert_allclose(
        XYZ_to_RLAB(XYZ, XYZ_n, Y_n, sigma),
        np.array([49.83, 54.87, 286.5, 1.1, np.nan, 15.57, -52.61]),
        rtol=0.01,
        atol=0.01,
    )