code: def test_multiple_same_fixed_features(self) -> None:
      node = GenerationNode(
          node_name="test",
          model_specs=[
              ModelSpec(
                  model_enum=Models.GPEI,
                  model_kwargs={},
                  model_gen_kwargs={
                      "n": 2,
                      "fixed_features": ObservationFeatures(
                          parameters={"x": 0}
                      ),
                  },
              ),
              ModelSpec(
                  model_enum=Models.GPEI,
                  model_kwargs={},
                  model_gen_kwargs={
                      "n": 3,
                      "fixed_features": ObservationFeatures(
                          parameters={"x": 0}
                      ),
                  },
              ),
          ],
      )
      self.assertEqual(
          node.fixed_features, ObservationFeatures(parameters={"x": 0})
      )
  
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 9 for calling the TestGenerationNode obj's underlying member method code with example usage: obj.test_multiple_same_fixed_features() without return types