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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 dump_next(self):
 """Dump the next reading from the stream. Returns: IOTileReading: The next reading or None if there isn't one """


        if self.dump_walker is None:
            return pack_error(ControllerSubsystem.SENSOR_LOG, SensorLogError.STREAM_WALKER_NOT_INITIALIZED)

        try:
            return self.dump_walker.pop()
        except StreamEmptyError:
            return None