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,
                     'dbpedia_resource') and self.dbpedia_resource is not None:
              _dict['dbpedia_resource'] = self.dbpedia_resource
          if hasattr(self, 'subtype') and self.subtype is not None:
              _dict['subtype'] = self.subtype
          return _dict