code: def setup(app):
      """Required Sphinx extension setup function."""
      app.add_directive(
          "bokeh-example-metadata", BokehExampleMetadataDirective
      )
  
      return PARALLEL_SAFE
  
file_path: bokeh/src/bokeh/sphinxext/bokeh_example_metadata.py
imports: from __future__ import annotations
  from sphinx.util import logging
  from docutils.parsers.rst.directives import unchanged
  from sphinx.errors import SphinxError
  from .None import PARALLEL_SAFE
  from .bokeh_directive import BokehDirective
  from .templates import EXAMPLE_METADATA
  from .util import get_sphinx_resources
label_desc: Use image node_id 1 for calling a global function with example usage: setup(app) and returns: PARALLEL_SAFE