code: def _step(self):
          
          try:
              new_value = self._device.get(self._channel)
              if new_value != self._value:
                  self._callback(new_value)
                  self._value = new_value
              time.sleep(self._polling_time)
          except:
              self.spine.log.exception("_PollingThread")
docs: Private method do not call it directly or override it.