const Operation& colocate_with_op) const;

  // Helper functions to get a unique names.
  string GetUniqueName(const string& prefix, bool check_single_use) const;
  string GetNameForOp(const string& default_name) const;

  bool single_use_scope() const { return scope_used_ != nullptr; }

  // The graph, status, and name maps are shared by all child scopes