code: def _length(self):
      return len(self._task_dataset) // self._batch_size
  
file_path: avalanche/tests/benchmarks/utils/test_replay_loader.py
imports: import unittest
  import numpy
  from avalanche.benchmarks.classic import SplitMNIST
  from avalanche.benchmarks.utils.data_loader import ReplayDataLoader
label_desc: Use image node_id 14 for calling the TestReplayDataLoader obj's underlying member method code with example usage: obj._length() and returns: unknown