def _combine_core_aux_specs(self):
        """Combine permutations over core and auxilliary Calc specs."""
        all_specs = []
        for core_dict in self._permute_core_specs():
            for aux_dict in self._permute_aux_specs():
                all_specs.append(_merge_dicts(core_dict, aux_dict))
        return all_specs
Combine permutations over core and auxilliary Calc specs.