def json(self):
        """add target to scores Dictionary

        Returns
        ----------
        json_string : str
            json dump of the scores dictionary
        """
        json_string = json.dumps(
            self.scores,
            indent=2,
            allow_nan=True
        )
        return json_string
add target to scores Dictionary

        Returns
        ----------
        json_string : str
            json dump of the scores dictionary