code: def __init__(self, benchmark: GenericCLScenario):
      self._benchmark = benchmark
      self._default_lcie = _LazyClassesInClassificationExps(
          benchmark, stream="train"
      )
  
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 1 to create a new _LazyStreamClassesInClassificationExps object from inherited base classes: Mapping with example: obj = _LazyStreamClassesInClassificationExps(benchmark)