def with_tags(self, *new_tags: Hashable) -> cirq.FrozenCircuit:
        """Creates a new tagged `FrozenCircuit` with `self.tags` and `new_tags` combined."""
        if not new_tags:
            return self
        new_circuit = FrozenCircuit(tags=self.tags + new_tags)
        new_circuit._moments = self._moments
        return new_circuit
Creates a new tagged `FrozenCircuit` with `self.tags` and `new_tags` combined.
cirq-core/cirq/circuits/frozen_circuit.py