def METHOD_NAME(self, alpha=None):
    """Update any of the parameters associated with this profile.
    Any parameter set to ``None`` won't be updated.
    Args:
        alpha (:obj:`float` or :obj:`str`): :math:`\\alpha` parameter, or
            set to ``'cosmo'`` to calculate the value from cosmology.
    """
    if alpha is not None and alpha != self.alpha:
        self.alpha = alpha