code: def flush(self):
      # We need to reset iteration here to avoid aggregating on the same data multiple
      # times
      logger.info(
          f"Interval Agg. Flushing: {self.key}; iteration: {self.iteration}; "
          f"aggregator: {self.aggregator.__class__.__name__}; points: {len(self.intermediate_values)}"
      )
      self.iteration = 0
      if self.intermediate_values:
          self.aggregator(self.key, self.intermediate_values)
      self.intermediate_values = []
      self.aggregator.flush()
  
imports: import logging
  from typing import Any, Dict, Iterable, List, Optional
  from reagent.core.tensorboardX import SummaryWriterContext
  from reagent.core.tracker import Aggregator, Observer
label_desc: Use image node_id 3 for calling the IntervalAggregatingObserver obj's underlying member method code with example usage: obj.flush() without return types