xbt_dynar_remove_at(visited_pairs, cursor, NULL);
xbt_dynar_insert_at(visited_pairs, cursor, &new_pair);
pair_test->visited_removed = 1;
xbt_dynar_remove_at(visited_pairs, cursor, NULL);
xbt_dynar_insert_at(visited_pairs, cursor, &new_pair);
pair_test->visited_removed = 1;