code: def notify_callback(self, notify):
          
          _LOGGER.debug(notify)
          if notify.ip_address != self.stb_ip:
              return
  
          if notify.tune:
              self._state = State.PLAYING_LIVE_TV 
              self.tune_src = notify.tune['@src']
              try:
                  if notify.stopped:
                      self._state = State.STOPPED
                  elif notify.timeshift:
                      self._state = State.PLAYING_TIMESHIFT_TV
                  elif notify.recorded:
                      self._state = State.PLAYING_RECORDED_TV
              except PyMediaroomError as e:
                  _LOGGER.debug("%s please report at https://github.com/dgomes/pymediaroom/issues", e)
          else:
              self._state = State.STANDBY
          
          _LOGGER.debug("%s is %s", self.stb_ip, self._state)
          return self._state
docs: Process State from NOTIFY message.