code: def _erase_buffer(self, output_buffer):
          
  
          erase_size = self._model.get(u'buffer_erase_size')
  
          buffer_type = u'storage'
          if output_buffer:
              buffer_type = u'streaming'
  
          old_readings = self._engine.popn(buffer_type, erase_size)
  
          # Now go through all of our walkers that could match and
          # update their availability counts and data buffer pointers
          for reading in old_readings:
              stream = DataStream.FromEncoded(reading.stream)
  
              for walker in self._queue_walkers:
                  # Only notify the walkers that are on this queue
                  if walker.selector.output == output_buffer:
                      walker.notify_rollover(stream)
docs: Erase readings in the specified buffer to make space.