code: async def serviceViewChanger(self, limit) -> int:
          
          if not self.isReady():
              return 0
          o = self.serviceViewChangerOutBox(limit)
          i = await self.serviceViewChangerInbox(limit)
          return o + i
docs: Service the view_changer's inBox, outBox and action queues.
  
          :return: the number of messages successfully serviced