code: def _get_model_reference(self, model_id):
      
      return ModelReference.from_api_repr(
          {"projectId": self.project, "datasetId": self.dataset_id, "modelId": model_id}
      )
docs: Constructs a ModelReference.
  
      Args:
          model_id (str): the ID of the model.
  
      Returns:
          google.cloud.bigquery.model.ModelReference:
              A ModelReference for a model in this dataset.