docs: def call_missing_reference(cls, kb_app, sphinx_app: Sphinx,
                                 sphinx_env: BuildEnvironment,
                                 node,
                                 contnode,
                                 ):
          """ On doctree-resolved, do callbacks"""
  
          for callback in EventAction.get_callbacks(kb_app,
                                                    SphinxEvent.MR):
              return callback(kb_app, sphinx_app, sphinx_env, node, contnode)