code: def classification_collate_mbatches_fn(mbatches):
      """Combines multiple mini-batches together.
  
      Concatenates each tensor in the mini-batches along dimension 0 (usually
      this is the batch size).
  
      :param mbatches: sequence of mini-batches.
      :return: a single mini-batch
      """
      batch = []
      for i in range(len(mbatches[0])):
          t = classification_single_values_collate_mbatches_fn(
              [el[i] for el in mbatches], i
          )
          batch.append(t)
      return batch
  
file_path: avalanche/avalanche/benchmarks/utils/collate_functions.py
imports: import itertools
  from abc import ABC, abstractmethod
  from collections import defaultdict
  from typing import List, TypeVar, Generic, Sequence, Tuple, Dict, Union, overload
  from typing_extensions import TypeAlias
  import torch
  from torch import Tensor
  from torch.utils.data import default_collate
label_desc: Use image node_id 1 for calling a global function with example usage: classification_collate_mbatches_fn(mbatches) and returns: batch