class_docstr: Definition of a learning experience based on a :class:`GenericCLScenario`
  instance.
  
  This experience implementation uses the generic experience-patterns
  assignment defined in the :class:`GenericCLScenario` instance. Instances of
  this class are usually obtained from a benchmark stream.
code: def benchmark(self) -> ClassificationScenario:
      bench = self._benchmark
      ClassificationExperience._check_unset_attribute(
          "benchmark", bench
      )
      return bench
  
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 2 for calling the ClassificationExperience obj's underlying member method code with example usage: obj.benchmark() and returns: bench