def get_digits(self, key: cirq.MeasurementKey, index=-1) -> tuple[int, ...]:
        """Gets the values of the qubits that were measured into this key.

        For example, if the measurement of qubits [q0, q1] produces [0, 1],
        this function will return (0, 1).

        Args:
            key: The measurement key.
            index: If multiple measurements have the same key, the index
                argument can be used to specify which measurement to retrieve.
                Here `0` refers to the first measurement, and `-1` refers to
                the most recent.

        Raises:
            KeyError: If the key has not been used or if the index is out of
                bounds.
        """
Gets the values of the qubits that were measured into this key.

        For example, if the measurement of qubits [q0, q1] produces [0, 1],
        this function will return (0, 1).

        Args:
            key: The measurement key.
            index: If multiple measurements have the same key, the index
                argument can be used to specify which measurement to retrieve.
                Here `0` refers to the first measurement, and `-1` refers to
                the most recent.

        Raises:
            KeyError: If the key has not been used or if the index is out of
                bounds.
        
cirq-core/cirq/value/classical_data.py