code: def _verify_and_add_jwt():
      
      if not app_context_has_jwt_data():
          guard = current_guard()
          token = guard.read_token_from_header()
          jwt_data = guard.extract_jwt_token(token)
          add_jwt_data_to_app_context(jwt_data)
docs: This helper method just checks and adds jwt data to the app context. Will
      not add jwt data if it is already present. Only use in this module