// size `nx`.
//
// Gradient nodes are automatically named under the "gradients/" prefix. To
// guarantee name uniqueness, subsequent calls to the same graph will
// append an incremental tag to the prefix: "gradients_1/", "gradients_2/", ...
// See TF_AddGradientsWithPrefix, which provides a means to specify a custom
// name prefix for operations added to a graph to compute the gradients.
//

  ///
  /// Plugins:
  ///   * Must set `status` to `TF_OK` if `region` was updated.
  ///   * Must set `status` to `TF_NOT_FOUND` if `path` doesn't point to an
  ///     existing file or one of the parent entries in `path` doesn't exist.
  ///   * Must set `status` to `TF_FAILED_PRECONDITION` if `path` points to a
  ///     directory or if it is invalid.
  ///   * Must set `status` to `TF_INVALID_ARGUMENT` if `path` points to an