code: def setUp(self) -> None:
      self.model_kwargs = {"init_position": 5}
      self.sobol_generation_step = GenerationStep(
          model=Models.SOBOL,
          num_trials=5,
          model_kwargs=self.model_kwargs,
      )
      self.model_spec = ModelSpec(
          # pyre-fixme[6]: For 1st param expected `ModelRegistryBase` but got
          #  `Union[typing.Callable[..., ModelBridge], ModelRegistryBase]`.
          model_enum=self.sobol_generation_step.model,
          model_kwargs=self.model_kwargs,
          model_gen_kwargs=None,
      )
  
imports: import logging
  from logging import Logger
  from unittest.mock import patch, PropertyMock
  from ax.core.base_trial import TrialStatus
  from ax.core.observation import ObservationFeatures
  from ax.exceptions.core import UserInputError
  from ax.modelbridge.cross_validation import DiagnosticCriterion, MetricAggregation, SingleDiagnosticBestModelSelector
  from ax.modelbridge.factory import get_sobol
  from ax.modelbridge.generation_node import GenerationNode, GenerationStep
  from ax.modelbridge.model_spec import FactoryFunctionModelSpec, ModelSpec
  from ax.modelbridge.registry import Models
  from ax.modelbridge.transition_criterion import MaxTrials
  from ax.utils.common.logger import get_logger
  from ax.utils.common.testutils import TestCase
  from ax.utils.testing.core_stubs import get_branin_experiment
  from ax.utils.testing.mock import fast_botorch_optimize
label_desc: Use image node_id 1 for calling the TestGenerationStep obj's underlying member method code with example usage: obj.setUp() without return types