docs: def _to_dict(self):
          """Return a json dictionary representing this model."""
          _dict = {}
          if hasattr(self, 'description') and self.description is not None:
              _dict['description'] = self.description
          if hasattr(self,
                     'destination_field') and self.destination_field is not None:
              _dict['destination_field'] = self.destination_field
          if hasattr(self, 'source_field') and self.source_field is not None:
              _dict['source_field'] = self.source_field
          if hasattr(self, 'overwrite') and self.overwrite is not None:
              _dict['overwrite'] = self.overwrite
          if hasattr(self,
                     'enrichment_name') and self.enrichment_name is not None:
              _dict['enrichment'] = self.enrichment_name
          if hasattr(self, 'ignore_downstream_errors'
                    ) and self.ignore_downstream_errors is not None:
              _dict['ignore_downstream_errors'] = self.ignore_downstream_errors
          if hasattr(self, 'options') and self.options is not None:
              _dict['options'] = self.options._to_dict()
          return _dict