def _with_measurement_key_mapping_(self, key_map: Mapping[str, str]):
        """Return a copy of this object with the measurement keys remapped.

        This method allows measurement keys to be reassigned at runtime.
        """
Return a copy of this object with the measurement keys remapped.

        This method allows measurement keys to be reassigned at runtime.
        
cirq-core/cirq/protocols/measurement_key_protocol.py