code: def test_default_config(config_app):
      """Test the default Sphinx-Gallery configuration is loaded
  
      if only the extension is added to Sphinx"""
  
      cfg = config_app.config
      assert cfg.project == "Sphinx-Gallery <Tests>"
      # no duplicate values allowed The config is present already
      with pytest.raises(ExtensionError) as excinfo:
          config_app.add_config_value("sphinx_gallery_conf", "x", True)
      assert "already present" in str(excinfo.value)
  
file_path: tensorly/doc/sphinx_ext/sphinx_gallery/tests/test_gen_gallery.py
imports: from __future__ import division, absolute_import, print_function, unicode_literals
  import os
  import tempfile
  import shutil
  import pytest
  from sphinx.application import Sphinx
  from sphinx.errors import ExtensionError
  from sphinx_gallery.gen_rst import MixedEncodingStringIO
  from sphinx_gallery.gen_gallery import DEFAULT_GALLERY_CONF
  from sphinx_gallery import sphinx_compatibility
label_desc: Use image node_id 4 for calling a global function with example usage: test_default_config(config_app) without return types