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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 _add_zone(self, zone, name='', status=Zone.CLEAR, expander=False):
 """ Adds a zone to the internal zone list. :param zone: zone number :type zone: int :param name: human readable zone name :type name: string :param status: zone status :type status: int """

        if not zone in self._zones:
            self._zones[zone] = Zone(zone=zone, name=name, status=None, expander=expander)

        self._update_zone(zone, status=status)