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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def Lab_to_XYZ(cobj, *args, **kwargs):
 """ Convert from Lab to XYZ """

    illum = cobj.get_illuminant_xyz()
    xyz_y = (cobj.lab_l + 16.0) / 116.0
    xyz_x = cobj.lab_a / 500.0 + xyz_y
    xyz_z = xyz_y - cobj.lab_b / 200.0

    if math.pow(xyz_y, 3) > color_constants.CIE_E:
        xyz_y = math.pow(xyz_y, 3)
    else:
        xyz_y = (xyz_y - 16.0 / 116.0) / 7.787

    if math.pow(xyz_x, 3) > color_constants.CIE_E:
        xyz_x = math.pow(xyz_x, 3)
    else:
        xyz_x = (xyz_x - 16.0 / 116.0) / 7.787

    if math.pow(xyz_z, 3) > color_constants.CIE_E:
        xyz_z = math.pow(xyz_z, 3)
    else:
        xyz_z = (xyz_z - 16.0 / 116.0) / 7.787

    xyz_x = (illum["X"] * xyz_x)
    xyz_y = (illum["Y"] * xyz_y)
    xyz_z = (illum["Z"] * xyz_z)

    return XYZColor(
        xyz_x, xyz_y, xyz_z, observer=cobj.observer, illuminant=cobj.illuminant)