code: def link_to_storage(self, sensor_log):
          
  
          if self.walker is not None:
              self._sensor_log.destroy_walker(self.walker)
              self.walker = None
  
          self.walker = sensor_log.create_walker(self.selector)
          self._sensor_log = sensor_log
docs: Attach this DataStreamer to an underlying SensorLog.
  
          Calling this method is required if you want to use this DataStreamer
          to generate reports from the underlying data in the SensorLog.
  
          You can call it multiple times and it will unlink itself from any
          previous SensorLog each time.
  
          Args:
              sensor_log (SensorLog): Actually create a StreamWalker to go along with this
                  streamer so that we can check if it's triggered.