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