// Thin wrapper around a FunctionDef.
class GraphFunction : public AbstractFunction {
 public:
  explicit GraphFunction(FunctionDef fdef);
  ~GraphFunction() override;

  // GraphFunction maybe stay alive for the duration of the returned
  // FunctionDef.
  Status GetFunctionDef(const FunctionDef** fdef) override;

  // Returns a shared reference to the wrapped function.
  absl::StatusOr<core::RefCountPtr<FunctionRecord>> GetFunctionRecord()

    mutex_lock session_lock(session->mu);
    const Graph& graph = session->graph->graph;

    const string& mutation_warning = session->graph->sessions[session];
    if (!mutation_warning.empty()) {
      // TODO(b/74949947): turn this back into an error status
      LOG(WARNING) << mutation_warning;
      session->graph->sessions[session].clear();
    }

    const auto num_nodes = graph.num_node_ids();

    const char* description, TF_Status* status);

// Returns the name of the graph function.
// The return value points to memory that is only usable until the next
// mutation to *func.
TF_CAPI_EXPORT extern const char* TF_FunctionName(TF_Function* func);

// Write out a serialized representation of `func` (as a FunctionDef protocol

  // value records whether the graph has been mutated since the corresponding
  // session has been run (this is detected in RecordMutation function). If the
  // string is empty, no mutation has occurred. Otherwise the string is a
  // description of the mutation suitable for returning to the user.
  //
  // Sessions are added to this map in TF_NewSession, and removed in
  // TF_DeleteSession.
  // TF_Graph may only / must be deleted when

      dist_mgr->GetCoordinationServiceAgent();
  if (coord_agent == nullptr) {
    status->status = tensorflow::errors::FailedPrecondition(
        "Coordination service is not enabled.");
    return;
  }
  absl::Duration timeout;
  if (timeout_in_ms > 0) {
    timeout = absl::Milliseconds(timeout_in_ms);
  } else {
    // Block until the key-value is set or the worker shuts down.
    timeout = absl::InfiniteDuration();
  }