def to_cosmology(cosmo, *args):
    """Return the |Cosmology| unchanged.

    Parameters
    ----------
    cosmo : `~astropy.cosmology.Cosmology`
        The cosmology to return.
    *args
        Not used.

    Returns
    -------
    `~astropy.cosmology.Cosmology` subclass instance
        Just ``cosmo`` passed through.
    """
    return cosmo