//
// We assume each node has a trivial path to itself so the returned set includes
// 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);