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