code: public com.google.cloud.datalabeling.v1beta1.NormalizedPolylineOrBuilder
        getNormalizedPolylineOrBuilder() {
      if (polyCase_ == 3) {
        return (com.google.cloud.datalabeling.v1beta1.NormalizedPolyline) poly_;
      }
      return com.google.cloud.datalabeling.v1beta1.NormalizedPolyline.getDefaultInstance();
    }
docs: <code>.google.cloud.datalabeling.v1beta1.NormalizedPolyline normalized_polyline = 3;</code>