code: def new_media_status(self, media_status):
          
          casts = self._casts
          group_members = self._mz.members
          for member_uuid in group_members:
              if member_uuid not in casts:
                  continue
              for listener in list(casts[member_uuid]['listeners']):
                  listener.multizone_new_media_status(
                      self._group_uuid, media_status)
docs: Handle reception of a new MediaStatus.