Convert to a stringified json object.

        This is the same as _as_json with the exception that it isn't
        a property, meaning that we can actually pass arguments...
        :param indent: indent argument to dumps
        :param kwargs: other arguments for dumps
        :return: JSON formatted string

def _as_json_dumps(self, indent: str='   ', **kwargs) -> str:
        """ Convert to a stringified json object.

        This is the same as _as_json with the exception that it isn't
        a property, meaning that we can actually pass arguments...
        :param indent: indent argument to dumps
        :param kwargs: other arguments for dumps
        :return: JSON formatted string
        """
        return json.dumps(self, default=self._default, indent=indent, **kwargs)