docs: def document(info=None, input=None, output=None):
      """
      Add extra information about request handler and its params
      """
      def wrapper(func):
          if info is not None:
              setattr(func, "_swg_info", info)
          if input is not None:
              setattr(func, "_swg_input", input)
          if output is not None:
              setattr(func, "_swg_output", output)
          return func
  
      return wrapper