Convert distance/s to units of UnitConverter.

        Converts distance/s from motor encoder counts to that of this
        UnitConverter.

        Parameters
        ----------
        distance : int, float, or iterable of ints and floats
            The distance/s to convert.

        Returns
        -------
        converted_distance : float or list of floats
            The converted distance/s.

def to_unit_distance(self, distance):
        """ Convert distance/s to units of UnitConverter.

        Converts distance/s from motor encoder counts to that of this
        UnitConverter.

        Parameters
        ----------
        distance : int, float, or iterable of ints and floats
            The distance/s to convert.

        Returns
        -------
        converted_distance : float or list of floats
            The converted distance/s.

        """
        if isinstance(distance, collections.Iterable):
            return [(x / self._distance_to_motor) for x in distance]
        else:
            return distance / self._distance_to_motor