const string unique_suffix = absl::StrCat("_", GetUniqueScopeId());

  std::vector<Node*> starts;
  starts.push_back(start);
  auto enter = [&](Node* n) { AddOrAppendXlaInternalScope(n, unique_suffix); };
  ReverseDFSFrom(*graph_, starts, enter, /*leave=*/nullptr,
                 /*stable_comparator=*/NodeComparatorName());
}

void ClusterScopingPassImpl::AddScopeToAllTransitiveSuccessors(Node* start) {