code: def _validate_game_object(self, op="unknown"):
          
          if self._g is None:
              raise ValueError(
                  "Game must be instantiated properly before using - call new_game() "
                  "or load_game(jsonstr='{...}')"
              )
          if not isinstance(self._g, GameObject):
              raise TypeError(
                  "Unexpected error during {0}! GameObject (_g) is not a GameObject!".format(op)
              )
docs: A helper method to provide validation of the game object (_g). If the
          game object does not exist or if (for any reason) the object is not a GameObject,
          then an exception will be raised.
  
          :param op: A string describing the operation (e.g. guess, save, etc.) taking place
          :return: Nothing