// APIs for Counter without label.
typedef struct TFE_MonitoringCounter0 TFE_MonitoringCounter0;
// Returns a new Counter metric object. The caller should manage lifetime of
// the object. Using duplicate metric name will crash the program with fatal
// error.
TF_CAPI_EXPORT extern TFE_MonitoringCounter0* TFE_MonitoringNewCounter0(
    const char* name, TF_Status* status, const char* description);
// Deletes the Counter object.

  // 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.
  //

  /// this method must take ownership of the returned pointer.
  ///
  /// The implementation should clean up paths, including but not limited to,
  /// removing duplicate `/`s, and resolving `..` and `.`.
  ///
  /// Plugins must not return `nullptr`. Returning empty strings is allowed.
  ///
  /// The allocation and freeing of memory must happen via the functions sent to