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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 multizone_member_added(self, member_uuid):
 """Handle added audio group member."""

        casts = self._casts
        if member_uuid not in casts:
            casts[member_uuid] = {'listeners': [],
                                  'groups': set()}
        casts[member_uuid]['groups'].add(self._group_uuid)
        for listener in list(casts[member_uuid]['listeners']):
            listener.added_to_multizone(self._group_uuid)