code: def save(self):
          
          data = super().save()
          data['levels'] = self.levels
          if self.parsers is None:
              data['parsers'] = None
          else:
              data['parsers'] = [parser.save() for parser in self.parsers]
          return data
docs: Convert to JSON.
  
          Returns
          -------
          `dict`
              JSON data.