n->AddAttr(attr_name, value);
}

// Step 1 for `PreprocessEdgesBetweenOutsideCompilations`. See comments of
// `PreprocessEdgesBetweenOutsideCompilations` for details.
Status PreprocessControlEdgesBetweenOutsideCompilations(
    Graph* g, const string& outside_compilation_attr_name) {
  // Gather edges to remove. We should not remove the edge while iterating.
  std::vector<const Edge*> edges_to_remove;