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

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)