code: def find_common_transforms_group(
      datasets: Iterable[Any], default_group: str = "train"
  ) -> str:
      """
      Utility used to find the common transformations group across multiple
      datasets.
  
      To compute the common group, the current one is used. Objects which are not
      instances of :class:`AvalancheDataset` are ignored.
      If no common group is found, then the default one is returned.
  
      :param datasets: The list of datasets.
      :param default_group: The name of the default group.
      :returns: The name of the common group.
      """
      # Find common "current_group" or use "train"
      uniform_group: Optional[str] = None
      for d_set in datasets:
          if isinstance(d_set, AvalancheDataset):
              if uniform_group is None:
                  uniform_group = (
                      d_set._flat_data._transform_groups.current_group
                  )
              else:
                  if (
                      uniform_group
                      != d_set._flat_data._transform_groups.current_group
                  ):
                      uniform_group = None
                      break
  
      if uniform_group is None:
          initial_transform_group = default_group
      else:
          initial_transform_group = uniform_group
  
      return initial_transform_group
  
imports: from collections import OrderedDict, defaultdict, deque
  from typing import TYPE_CHECKING, Any, Callable, Generic, Iterator, List, Iterable, Mapping, Optional, Sequence, TypeVar, Union, Dict, SupportsInt
  import warnings
  import torch
  from torch import Tensor
  from torch.utils.data import Subset, ConcatDataset
  from .data import AvalancheDataset
  from .data_attribute import DataAttribute
  from .dataset_definitions import ISupportedClassificationDataset
  from .dataset_utils import SubSequence, find_list_from_index
  from .flat_data import ConstantSequence
  from .transform_groups import TransformGroupDef, TransformGroups, XTransform, YTransform
label_desc: Use image node_id 9 for calling a global function with example usage: find_common_transforms_group(datasets, default_group) and returns: initial_transform_group