code: def json_data(self):
          
          def stringify_keys(d):
              if not isinstance(d, dict):
                  return d
              return dict((str(k), stringify_keys(v)) for k, v in d.items())
          data = self.make_data()
          json_data = json.dumps(stringify_keys(data))
          return json_data
docs: Returns data as JSON
          
          Returns:
            json_data (str): JSON representation of data, as created in make_data