def dump_all_json_fields_to_str(cls, model_dict: Dict) -> Dict:
        """
        Receives dictionary of model that is about to be saved and changes
        all json fields into strings

        :param model_dict: dictionary of model that is about to be saved
        :type model_dict: Dict
        :return: dictionary of model that is about to be saved
        :rtype: Dict
        """
        for key, value in model_dict.items():
            if key in cls._json_fields:
                model_dict[key] = encode_json(value)
        return model_dict

        Receives dictionary of model that is about to be saved and changes
        all json fields into strings

        :param model_dict: dictionary of model that is about to be saved
        :type model_dict: Dict
        :return: dictionary of model that is about to be saved
        :rtype: Dict
        
ormar/models/mixins/save_mixin.py