code: def _get_split(super_categories, train_set):
      """Get number of classes per experience, and
      the total order of the classes."""
      per_exp_classes, fixed_class_order = {}, []
      for idx, supcat in enumerate(super_categories):
          new_cats = list(train_set.cats_per_supcat[supcat])
          fixed_class_order += new_cats
          per_exp_classes[idx] = len(new_cats)
      return per_exp_classes, fixed_class_order
  
file_path: avalanche/avalanche/benchmarks/classic/cinaturalist.py
imports: from pathlib import Path
  from typing import Union, Any, Optional
  from avalanche.benchmarks.classic.classic_benchmarks_utils import check_vision_benchmark
  from avalanche.benchmarks.datasets import INATURALIST2018, default_dataset_location
  from avalanche.benchmarks import nc_benchmark
  from torchvision import transforms
label_desc: Use image node_id 3 for calling a global function with example usage: _get_split(super_categories, train_set) and returns: per_exp_classes,  fixed_class_order