code: def check_config(app):
      if not app.config.googleanalytics_id:
          raise ExtensionError(
              "'googleanalytics_id' config value must be set "
              "for ga statistics to function properly."
          )
  
imports: from sphinx.errors import ExtensionError
label_desc: Use image node_id 2 for calling a global function with example usage: check_config(app) without return types