docs: def _to_dict(self):
          """Return a json dictionary representing this model."""
          _dict = {}
          if hasattr(self, 'text') and self.text is not None:
              _dict['text'] = self.text
          if hasattr(self, 'created') and self.created is not None:
              _dict['created'] = datetime_to_string(self.created)
          if hasattr(self, 'updated') and self.updated is not None:
              _dict['updated'] = datetime_to_string(self.updated)
          return _dict