The competence function for MatrixMetropolis

def competence(s):
        """
        The competence function for MatrixMetropolis
        """
        # MatrixMetropolis handles the Wishart family, which are valued as
        # _symmetric_ matrices.
        if any([isinstance(s, cls)
                for cls in [distributions.Wishart, distributions.WishartCov]]):
            return 2
        else:
            return 0