code: def test_lock(dvc):
      stage = create_stage(PipelineStage, dvc, **kwargs)
      assert to_single_stage_lockfile(stage) == {"cmd": "command"}
  
imports: from collections import OrderedDict
  import pytest
  from voluptuous import Schema
  from dvc.dvcfile import PROJECT_FILE
  from dvc.schema import LOCK_FILE_STAGE_SCHEMA, LOCKFILE_STAGES_SCHEMA
  from dvc.stage import PipelineStage, create_stage
  from dvc.stage.serialize import DEFAULT_PARAMS_FILE, to_lockfile
  from dvc.stage.serialize import to_single_stage_lockfile
  from dvc.stage.utils import split_params_deps
  from dvc_data.hashfile.hash_info import HashInfo
label_desc: Use image node_id 2 for calling a global function with example usage: test_lock(dvc) without return types