code: def _json_body_(cls):
          
          json = []
          for series_name, data in six.iteritems(cls._datapoints):
              json.append({'name': series_name,
                           'columns': cls._fields,
                           'points': [[getattr(point, k) for k in cls._fields]
                                      for point in data]
                           })
          return json
docs: Return JSON body of the datapoints.
  
          :return: JSON body of the datapoints.