code: def batchsize(self):
      return len(self)
  
imports: from __future__ import annotations
  from typing import Tuple
  from collections import Counter
  from parlai.core.torch_agent import TorchAgent
  from parlai.core.metrics import Metric, SumMetric
  from parlai.core.message import Message
label_desc: Use image node_id 1 for calling the FakeList obj's underlying member method code with example usage: obj.batchsize() and returns: len