def list_calibrations(
        self,
        earliest_timestamp: datetime.datetime | datetime.date | int | None = None,
        latest_timestamp: datetime.datetime | datetime.date | int | None = None,
    ) -> list[calibration.Calibration]:
        """Retrieve metadata about a specific calibration run.

        Args:
            earliest_timestamp: The earliest timestamp of a calibration
                to return in UTC.
            latest_timestamp: The latest timestamp of a calibration to
                return in UTC.

        Returns:
            The list of calibration data with the most recent first.
        """
Retrieve metadata about a specific calibration run.

        Args:
            earliest_timestamp: The earliest timestamp of a calibration
                to return in UTC.
            latest_timestamp: The latest timestamp of a calibration to
                return in UTC.

        Returns:
            The list of calibration data with the most recent first.
        
cirq-google/cirq_google/engine/abstract_processor.py