code: def __getitem__(
      self, exp_id: Union[int, slice]
  ) -> LazyClassesInExpsRet:
      indexing_collate = _LazyClassesInClassificationExps._slice_collate
      result = manage_advanced_indexing(
          exp_id,
          self._get_single_exp_classes,
          len(self),
          indexing_collate,
      )
      return result
  
imports: from typing import Callable, TypeVar, Union, Sequence, Optional, Iterable, List, Set, Tuple, Mapping, overload, TYPE_CHECKING
  import warnings
  from avalanche.benchmarks.scenarios.deprecated import AbstractClassTimelineExperience
  from avalanche.benchmarks.scenarios.deprecated.dataset_scenario import ClassesTimelineCLScenario, FactoryBasedStream, TStreamsUserDict
  from avalanche.benchmarks.utils.dataset_utils import manage_advanced_indexing
label_desc: Use image node_id 5 for calling the _LazyClassesInClassificationExps obj's underlying member method code with example usage: obj.__getitem__(exp_id) and returns: result