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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def high_limit(self) -> Optional[Union[int, float]]: """ High limit setting for a special sensor. For LS-10/LS-20 base units this is the alarm high limit. For LS-30 base units, this is either alarm OR control high limit, as indicated by special_status ControlAlarm bit flag. """

        return self._get_field_value(SpecialDevice.PROP_HIGH_LIMIT)