Returns
        -------
        prior_class_dict: {Prior: class}
            A dictionary mapping Priors to associated classes. Each prior will only have one class; if a prior is
            shared by two classes then only one of those classes will be in this dictionary.

def prior_class_dict(self):
        """
        Returns
        -------
        prior_class_dict: {Prior: class}
            A dictionary mapping Priors to associated classes. Each prior will only have one class; if a prior is
            shared by two classes then only one of those classes will be in this dictionary.
        """
        return {prior: cls
                for prior_model_tuple in self.prior_model_tuples
                for prior, cls in
                prior_model_tuple.prior_model.prior_class_dict.items()}