Returns
        -------
        constant_tuple_dict: {Constant: ConstantTuple}
            The set of all constants associated with this mapper

def constant_tuple_dict(self):
        """
        Returns
        -------
        constant_tuple_dict: {Constant: ConstantTuple}
            The set of all constants associated with this mapper
        """
        return {constant_tuple.constant: constant_tuple
                for name, prior_model in self.prior_model_tuples
                for constant_tuple in prior_model.constant_tuples}.values()