code: def setUp(self) -> None:
      experiment = get_branin_experiment()
      experiment.add_tracking_metric(
          BraninMetric(name="m2", param_names=["x1", "x2"])
      )
      sobol = Models.SOBOL(experiment.search_space)
      a = sobol.gen(5)
      experiment.new_batch_trial(generator_run=a).run()
      self.experiment = experiment
      self.metrics = list(experiment.metrics.values())
      self.metrics[0].lower_is_better = True
      self.metrics[1].lower_is_better = False
  
file_path: Ax/ax/plot/tests/long_running/test_pareto_utils.py
imports: from ax.exceptions.core import UnsupportedError
  from ax.metrics.branin import BraninMetric
  from ax.modelbridge.registry import Models
  from ax.plot.pareto_utils import compute_posterior_pareto_frontier
  from ax.utils.common.testutils import TestCase
  from ax.utils.testing.core_stubs import get_branin_experiment
label_desc: Use image node_id 1 for calling the ComputePosteriorParetoFrontierTest obj's underlying member method code with example usage: obj.setUp() without return types