inline constexpr char kSavedModelTrainOpSignatureKey[] =
    "__saved_model_train_op";

// Key in the TensorBundle for the object graph proto.
inline constexpr char kObjectGraphProtoKey[] = "_CHECKPOINTABLE_OBJECT_GRAPH";

// Filename for the FingerprintDef protocol buffer.
inline constexpr char kFingerprintFilenamePb[] = "fingerprint.pb";

}  // namespace tensorflow

                dtype: DT_STRING
                tensor_shape {
                  dim {
                    size: 1
                  }
                }
                string_val: "_CHECKPOINTABLE_OBJECT_GRAPH"
              }
            }
          }
        }
        node_def {
          name: "SaveV2/shape_and_slices"
          op: "Const"
          device: "/device:CPU:0"