class_docstr: Benchmark evaluator for NAS-Bench-201.
  
  Parameters
  ----------
  num_epochs
      Queried ``num_epochs``.
  dataset
      Queried ``dataset``.
  metric
      Queried metric.
  include_intermediates
      Whether to report intermediate results.
  
  See Also
  --------
  nni.nas.benchmark.nasbench201.query_nb201_trial_stats
  nni.nas.benchmark.nasbench201.Nb201TrialConfig
code: def default_space(cls) -> SlimBenchmarkSpace:
      operations = [
          "none",
          "skip_connect",
          "conv_1x1",
          "conv_3x3",
          "avg_pool_3x3",
      ]
      ops = [
          Categorical(operations, label="0_1"),
          Categorical(operations, label="0_2"),
          Categorical(operations, label="1_2"),
          Categorical(operations, label="0_3"),
          Categorical(operations, label="1_3"),
          Categorical(operations, label="2_3"),
      ]
      return SlimBenchmarkSpace({op.label: op for op in ops})
  
imports: from __future__ import annotations
  import itertools
  import logging
  import random
  import warnings
  from typing import Any, cast
  import nni
  from nni.mutable import Sample, Mutable, LabeledMutable, Categorical, CategoricalMultiple, label_scope
  from nni.nas.evaluator import Evaluator
  from nni.nas.space import ExecutableModelSpace
  from .space import SlimBenchmarkSpace
label_desc: Use image node_id 2 for calling the NasBench201Benchmark obj's underlying member method code with example usage: obj.default_space(cls) and returns: SlimBenchmarkSpace