code: public com.google.cloud.datalabeling.v1beta1.LabelImagePolylineOperationMetadata
        getImagePolylineDetails() {
      if (detailsCase_ == 12) {
        return (com.google.cloud.datalabeling.v1beta1.LabelImagePolylineOperationMetadata) details_;
      }
      return com.google.cloud.datalabeling.v1beta1.LabelImagePolylineOperationMetadata
          .getDefaultInstance();
    }
docs: <code>
  .google.cloud.datalabeling.v1beta1.LabelImagePolylineOperationMetadata image_polyline_details = 12;
  </code>