std::vector<Tensor> all_input_tensors;
  // Update the vector with information from `input_tensors` if provided.
  if (input_tensors != nullptr) {
    // Note that we take the address of the elements in `all_input_tensors`
    // below. Allocate enough space so that no reallocation happens, which will
    // make the pointers invalid.
    all_input_tensors.reserve(num_inputs);

  };
  return tensorflow::unwrap(cancellation_manager)
      ->RegisterCallbackWithErrorLogging(token, callback, callback_name);
}

bool TFE_CancellationManagerDeregisterCallback(
    TFE_CancellationManager* cancellation_manager,
    TFE_CancellationToken token) {
  return tensorflow::unwrap(cancellation_manager)->DeregisterCallback(token);
}

bool TFE_CancellationManagerTryDeregisterCallback(