code: def test_min_trials_observed(self) -> None:
      with self.assertRaisesRegex(
          UserInputError, "min_trials_observed > num_trials"
      ):
          GenerationStep(
              model=Models.SOBOL,
              num_trials=5,
              min_trials_observed=10,
              model_kwargs=self.model_kwargs,
          )
  
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 3 for calling the TestGenerationStep obj's underlying member method code with example usage: obj.test_min_trials_observed() without return types