message: Code review: add some comments on three_clique_indices
diff: @@ -141,6 +141,7 @@ class Flag_complex_sparse_matrix {
  return false;
  }
  + // Returns the edges connecting u and v (extremities of crit) to their common neighbors (not themselves)
  std::set<Row_index> three_clique_indices(Row_index crit) {
  std::set<Row_index> edge_indices;
  