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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 _step(self):
 """Private method do not call it directly or override it."""

        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")