virtual Status AddParameter(DataType dtype, const PartialTensorShape& shape,
                              TracingTensorHandle**) = 0;

  // Finalize this context and make a function out of it. The context is in a
  // invalid state after this call and must be destroyed.
  virtual Status Finalize(OutputList* outputs, AbstractFunction**) = 0;

  // For LLVM style RTTI.
  static bool classof(const AbstractContext* ptr) {

//
// Does not use the operation's definition to determine how many inputs should
// be attached. It is intended for use with TFE_OpGetFlatInput to inspect an
// already-finalized operation.
//
// Note that TFE_OpGetFlatInputCount and TFE_OpGetFlatInput operate on a flat
// sequence of inputs, unlike TFE_OpGetInputLength (for getting the length of a

  /// core TensorFlow upon registration (see the `TF_FilesystemPluginInfo`
  /// structure in Section 4).
  ///
  /// Plugins:
  ///   * Must set `status` to `TF_OK` if transaction successfuly finalized.
  ///   * Must set `status` to `TF_NOT_FOUND` if token is invalid/not found
  ///   * Might use any other error value for `status` to signal other errors.
  int (*end_transaction)(const TF_Filesystem* filesystem,