@classmethod
def get_duration(cls, start, end):
    """
        Assuming that `start` and `end` are values in seconds, calculate the result as the
        time difference between the two values.

        The result is expressed with the units and precision of the class's internal state.

        Returns
        -------
        duration : int or float
            Returns float value if `time_ndigits` is non-zero, otherwise an int value.

        """
    duration = (end - start) * cls._time_multiplier
    return cls._time_func(duration, cls._time_ndigits
        ) if cls._time_ndigits else cls._time_func(duration)
