def builtin_timescale(cls, name):
        """
        Generate a default timescale legend. No arguments.

        Returns:
            Legend: The timescale stored in `defaults.py`.
        """
        names = {
                 'isc': TIMESCALE__ISC,
                 'usgs_isc': TIMESCALE__USGS_ISC,
                 'dnag': TIMESCALE__DNAG,
                 }
        return cls.from_csv(text=names[name.lower()])
Generate a default timescale legend. No arguments.

        Returns:
            Legend: The timescale stored in `defaults.py`.