code: def flush(self):
      if self.values:
          self.epoch_values = self.values
          self.values = []
  
imports: import logging
  from collections import deque
  from typing import Any, Callable, Deque, Dict, List, Optional
  import numpy
  import torch
  from reagent.core.tensorboardX import SummaryWriterContext
  from reagent.core.tracker import Aggregator
label_desc: Use image node_id 3 for calling the LastEpochListAggregator obj's underlying member method code with example usage: obj.flush() without return types