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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 update(self):
 """Update the battery state."""

        self._controller.update(self._id, wake_if_asleep=False)
        data = self._controller.get_charging_params(self._id)
        if data:
            self.__battery_level = data['battery_level']
            self.__charging_state = data['charging_state']