code: def test_config_old_backreferences_conf(config_app):
      """Testing Deprecation warning message against old backreference config
  
      In this case the user is required to update the mod_example_dir config
      variable Sphinx-Gallery should notify the user and also silently update
      the old config to the new one."""
  
      cfg = config_app.config
      assert cfg.project == "Sphinx-Gallery <Tests>"
      assert cfg.sphinx_gallery_conf[
          "backreferences_dir"
      ] == os.path.join("modules", "gen")
      build_warn = config_app._warning.getvalue()
  
      assert "WARNING:" in build_warn
      assert "Old configuration" in build_warn
      assert "mod_example_dir" in build_warn
      assert "Gallery now requires" in build_warn
      assert "For a quick fix" in build_warn
      assert "'backreferences_dir': False" not in build_warn
  
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 5 for calling a global function with example usage: test_config_old_backreferences_conf(config_app) without return types