return nullptr;
  }

  bool GetCurrentThreadName(tsl::string* name) override { return false; }

  void SchedClosure(absl::AnyInvocable<void()> closure) override {}

  void SchedClosureAfter(int64_t micros,
                         absl::AnyInvocable<void()> closure) override {}

  absl::Status LoadDynamicLibrary(const char* library_filename,
                                  void** handle) override {