Returns
        -------
        priors: [Prior]
            An ordered list of unique priors associated with this mapper

def prior_tuples_ordered_by_id(self):
        """
        Returns
        -------
        priors: [Prior]
            An ordered list of unique priors associated with this mapper
        """
        return sorted(list(self.prior_tuples), key=lambda prior_tuple: prior_tuple.prior.id)