docs: def _to_dict(self):
          """Return a json dictionary representing this model."""
          _dict = {}
          if hasattr(self, 'name') and self.name is not None:
              _dict['name'] = self.name
          if hasattr(self, 'language') and self.language is not None:
              _dict['language'] = self.language
          if hasattr(self, 'rate') and self.rate is not None:
              _dict['rate'] = self.rate
          if hasattr(self, 'url') and self.url is not None:
              _dict['url'] = self.url
          if hasattr(
                  self,
                  'supported_features') and self.supported_features is not None:
              _dict['supported_features'] = self.supported_features._to_dict()
          if hasattr(self, 'description') and self.description is not None:
              _dict['description'] = self.description
          return _dict