// need for `Env::Default()`. At that time, we might decide to remove the need
// for `Env::Default()` altogether, but that's a different project, not in
// scope for now. I'm just mentioning this here as that transition will mean
// removal of the registration part from `Env` and adding it here instead: we
// will need tables to hold for each scheme the function tables that implement
// the needed functionality instead of the current `FileSystemRegistry` code in

  // be executed as an op. Return error if the function with the same name
  // already exists.
  virtual Status AddFunctionDef(const FunctionDef& fdef) = 0;

  // Notifies about the function removal.
  virtual Status AddRemoveFunctionNotifier(const string& func,
                                           std::function<void()> notifier) = 0;

  // Same as `AddFunctionDef`, but additionally saves the `stack_traces` under

///   `status` out variable should be updated accordingly (e.g., to include
///   plugin version information that relates to the condition change).
///
/// All other changes to the data structures (e.g., method removal, method
/// reordering, argument reordering, adding or removing arguments, changing the
/// type or the constness of a parameter, etc.) results in an ABI breakage.

        and `tf.version.`. Moving all constants under `tf.saved_model`
        submodules to `tf.saved_model` module. New endpoints are added in V1 and
        V2 but existing endpoint removals are only applied in V2.
    *   Deprecates behavior where device assignment overrides collocation
        constraints inside a collocation context manager.
*   Keras & Python API