code: def setup(app):
      """Setup as a sphinx extension."""
  
      # This is only a lexer, so adding it below to pygments appears sufficient.
      # But if somebody knows what the right API usage should be to do that via
      # sphinx, by all means fix it here.  At least having this setup.py
      # suppresses the sphinx warning we'd get without it.
      metadata = {
          "parallel_read_safe": True,
          "parallel_write_safe": True,
      }
      return metadata
  
label_desc: Use image node_id 1 for calling a global function with example usage: setup(app) and returns: metadata