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

void TFE_DeleteCancellationManager(
    TFE_CancellationManager* cancellation_manager) {
  delete tensorflow::unwrap(cancellation_manager);
}

void TFE_OpSetCancellationManager(TFE_Op* op,

    TFE_CancellationManager*, TFE_CancellationToken token);
TF_CAPI_EXPORT extern bool TFE_CancellationManagerTryDeregisterCallback(
    TFE_CancellationManager*, TFE_CancellationToken token);
TF_CAPI_EXPORT extern void TFE_DeleteCancellationManager(
    TFE_CancellationManager*);

// Associates the given `cancellation_manager` with `op`, so that invoking
// `TFE_CancellationManagerStartCancel(cancellation_manager)` will cancel the
// execution of `op`.