// all of the nodes that have ref variables as input or output.
absl::StatusOr<absl::flat_hash_set<Node*>> GetNodesRelatedToRefVariables(
    const Graph& graph, FunctionLibraryRuntime* lib_runtime);

// Deterministically serialized the graph to a byte string.
absl::StatusOr<std::string> SerializeGraphDeterministic(const Graph& graph);

        TF_GRAPH_DEF_VERSION, lib_def_.get(), opts,
        /*default_thread_pool=*/nullptr, /*cluster_flr=*/nullptr);
    flr_ = pflr_->GetFLR("/job:localhost/replica:0/task:0/cpu:0");
  }

  FunctionLibraryRuntime* flr_;
  std::unique_ptr<DeviceMgr> device_mgr_;
  std::unique_ptr<FunctionLibraryDefinition> lib_def_;
  std::unique_ptr<ProcessFunctionLibraryRuntime> pflr_;

  std::unique_ptr<OpKernel> kernel_;
};

// It takes vectors of constant and resource arguments explicitly.
// It does not have corresponding OpDef because it is never present
// in the GraphDef.
// Currently, it is used by eager runtime. FunctionLibraryRuntime creates
// this kernel when asked to create a kernel for an XLA-compiled function.
//
// `has_ref_vars`: whether the input computation can have reference variables.