code: def test_set_unset_default_viewers(
      settings_file, sample_viewer_config, sample_empty_viewer_config
  ):
      labconfig = LabConfig(settings_file=settings_file)
      labconfig.set_default_viewers()
      assert labconfig.config == sample_viewer_config
      labconfig.unset_default_viewers()
      assert labconfig.config == sample_empty_viewer_config
  
file_path: jupytext/tests/unit/test_labconfig.py
imports: import json
  import pytest
  from jupytext_config.labconfig import LabConfig
label_desc: Use image node_id 5 for calling a global function with example usage: test_set_unset_default_viewers(settings_file, sample_viewer_config, sample_empty_viewer_config) without return types