code: def test_get_baseline(tmp_dir, scm, dvc, exp_stage):
      init_rev = scm.get_rev()
      assert dvc.experiments.get_baseline(init_rev) is None
  
      results = dvc.experiments.run(
          exp_stage.addressing, params=["foo=2"]
      )
      exp_rev = first(results)
      assert dvc.experiments.get_baseline(exp_rev) == init_rev
  
      dvc.experiments.run(
          exp_stage.addressing, params=["foo=3"], queue=True
      )
      assert (
          dvc.experiments.get_baseline(f"{CELERY_STASH}@{{0}}")
          == init_rev
      )
  
      scm.add(
          [
              "dvc.yaml",
              "dvc.lock",
              "copy.py",
              "params.yaml",
              "metrics.yaml",
          ]
      )
      scm.commit("promote exp")
      promote_rev = scm.get_rev()
      assert dvc.experiments.get_baseline(promote_rev) is None
  
      results = dvc.experiments.run(
          exp_stage.addressing, params=["foo=4"]
      )
      exp_rev = first(results)
      assert dvc.experiments.get_baseline(exp_rev) == promote_rev
  
      dvc.experiments.run(
          exp_stage.addressing, params=["foo=5"], queue=True
      )
      assert (
          dvc.experiments.get_baseline(f"{CELERY_STASH}@{{0}}")
          == promote_rev
      )
      assert (
          dvc.experiments.get_baseline(f"{CELERY_STASH}@{{1}}")
          == init_rev
      )
  
imports: import itertools
  import logging
  import os
  import stat
  from textwrap import dedent
  import pytest
  from configobj import ConfigObj
  from funcy import first
  from dvc.dvcfile import PROJECT_FILE
  from dvc.env import DVC_EXP_BASELINE_REV, DVC_EXP_NAME, DVC_ROOT, DVC_STUDIO_OFFLINE, DVC_STUDIO_REPO_URL, DVC_STUDIO_TOKEN, DVC_STUDIO_URL
  from dvc.exceptions import DvcException, ReproductionError
  from dvc.repo.experiments.exceptions import ExperimentExistsError
  from dvc.repo.experiments.queue.base import BaseStashQueue
  from dvc.repo.experiments.refs import CELERY_STASH
  from dvc.repo.experiments.utils import exp_refs_by_rev
  from dvc.scm import SCMError, resolve_rev
  from dvc.stage.exceptions import StageFileDoesNotExistError
  from dvc.testing.scripts import COPY_SCRIPT
  from dvc.utils.serialize import PythonFileCorruptedError
label_desc: Use image node_id 5 for calling a global function with example usage: test_get_baseline(tmp_dir, scm, dvc, exp_stage) without return types