  void operator()(cudnnPersistentRNNPlan_t plan) const {
    CHECK_CUDNN_OK(cudnnDestroyPersistentRNNPlan(plan));
  }
  void operator()(cudnnPersistentRNNPlan_t plan) const {
    CHECK_CUDNN_OK(cudnnDestroyPersistentRNNPlan(plan));
  }