void TF_InitGraph(TP_OptimizerRegistrationParams* params, TF_Status* status);

// Get a set of node names that must be preserved. They can not be transformed
// or removed during the graph transformation. This includes feed and fetch
// nodes, keep_ops, init_ops. Fills in `num_values` and `storage_size`, they
// will be used in `TF_GetNodesToPreserveList`.

TF_CAPI_EXPORT extern void TFE_MonitoringStringGaugeCellSet(
    TFE_MonitoringStringGaugeCell* cell, const char* value);
// Retrieves the string value and saves it in the buffer.
TF_CAPI_EXPORT extern const void TFE_MonitoringStringGaugeCellValue(
    TFE_MonitoringStringGaugeCell* cell, TF_Buffer* buf);

// APIs for String Gauge without label.
typedef struct TFE_MonitoringStringGauge0 TFE_MonitoringStringGauge0;

  // worker/task/replica if any of those differ across components. Useful for
  // printing debug messages.
  std::vector<std::string> SummarizeDeviceNames() const;

 private:
  // A sequence of device names, indicating which devices replicated operations
  // are forwarded to.
  const std::vector<std::string> underlying_devices_;
  // A sequence of thread wrappers, one per device, for executing operations in
  // parallel.
  //

  TF_AttrType type;

  // Total size the attribute value.
  // The units of total_size depend on is_list and type.
  // (1) If type == TF_ATTR_STRING and is_list == 0
  //     then total_size is the byte size of the string
  //     valued attribute.
  // (2) If type == TF_ATTR_STRING and is_list == 1
  //     then total_size is the cumulative byte size
  //     of all the strings in the list.

// ignored (and hence can be None). The backprop algorithm can then leverage
// this by not constructing zeros to pass for those indices.
std::unordered_map<string, std::unordered_set<int>>*
FunctionsAcceptingNoneForIndicesMap() {
  static auto* const m =
      new std::unordered_map<string, std::unordered_set<int>>({
          {"SoftmaxCrossEntropyWithLogits", {1}},
          {"SparseSoftmaxCrossEntropyWithLogits", {1}},

  virtual const FunctionDef* FindFunctionDef(const string& name) const = 0;

  // Find and return a function record added by its name.
  virtual core::RefCountPtr<FunctionRecord> FindRecord(
      const string& name) const = 0;

  // Return the ParsedName of Host CPU device.
  virtual const DeviceNameUtils::ParsedName& HostCPUParsedName() const = 0;
  virtual const string& HostCPUName() const = 0;

  // the new one and remove the file from cache.
  bool ValidateAndUpdateFileSignature(const std::string& filename,
                                      int64_t file_signature)
      ABSL_LOCKS_EXCLUDED(mu_);

  /// Remove all cached blocks for `filename`.
  void RemoveFile(const std::string& filename) ABSL_LOCKS_EXCLUDED(mu_);

  /// Remove all cached data.
  void Flush() ABSL_LOCKS_EXCLUDED(mu_);

/// operation `foo` might have a default implementation which uses `bar` and
/// `foobar`. If the plugin supplies `bar` and `foobar`, TensorFlow can use the
/// default implementation of `foo`.
///
/// During plugin loading, plugins will call the registration function provided
/// by this interface, supplying values for each of these structures. Core
/// TensorFlow checks that the plugin supplies all mandatory operations and